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# Building a Boat

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I have a friend that is looking to build his own boat. His basic concept is a two person pedal boat that is capable of calm sea travel. Here are some of his plans:

* the boat is to be entirely self sufficient

* generators on the pedal gears and PV cells on top of the covering will charge batteries

* an electric motor can turn a "waterwheel" near the rudder when not paddling

* the boat frame will be made of cedar and filled with flotation foam for bouyancy

* he also mentioned making a small wind turbine up top, but I don't think it's possible for him to create much energy with it

* a solar still design to create drinking water

I'm probably forgetting some stuff, but I'll amend as needed and feel free to ask questions. I've got a few of my own...

Is there an easy calculation for determining how many watts it takes to push a boat through the water? (eg 10W can carry a 500kg boat 1km, or something like that) I realize the design of the boat factors in (as well as environmental conditions etc.), but I'm just looking for ballpark figures.

Is it better to make the generators, or can they be had cheaply enough?

Would it make sense to use a car alternator in this situation?

What materials are susceptible to brackish waters or should otherwise be avoided?

Any ideas on general design and building are greatly appreciated as well!

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Hey Freezy! Just to start with an unattested quote, "a boat is a hole in water that one throws money into."   That said, you guys may want to look into this guy's success pedaling a boat in an ocean:

I would have to ask my brother for the details. From memory it has to do with corrosion. I remember my brother saying they were diving down and applying the stuff underwater and thinking "wow, they

I have a friend that is looking to build his own boat. His basic concept is a two person pedal boat that is capable of calm sea travel. Here are some of his plans:

* the boat is to be entirely self sufficient

* generators on the pedal gears and PV cells on top of the covering will charge batteries

* an electric motor can turn a "waterwheel" near the rudder when not paddling

* the boat frame will be made of cedar and filled with flotation foam for bouyancy

* he also mentioned making a small wind turbine up top, but I don't think it's possible for him to create much energy with it

* a solar still design to create drinking water

I'm probably forgetting some stuff, but I'll amend as needed and feel free to ask questions. I've got a few of my own...

Is there an easy calculation for determining how many watts it takes to push a boat through the water? (eg 10W can carry a 500kg boat 1km, or something like that) I realize the design of the boat factors in (as well as environmental conditions etc.), but I'm just looking for ballpark figures.

Is it better to make the generators, or can they be had cheaply enough?

Would it make sense to use a car alternator in this situation?

What materials are susceptible to brackish waters or should otherwise be avoided?

Any ideas on general design and building are greatly appreciated as well!

Ok I am not familiar with ocean travels. #1 Cedar (or any wood) is going to be heavier than something made of aluminum or fiberglass resulting in more power needed to push it around.

I looked into generators for home (diy types). Car alternators take more input power to generate electricity than was acceptable for me. Look into motorcycle generators, they are smaller, they run 12 volt, you can find them at junk yards and swap meets, and motorcycle batteries are smaller.

Another aspect you might want to look into is electric chainsaws or weed wackers for your motor ideas.

Hope this adds something to the idea!

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Is there an easy calculation for determining how many watts it takes to push a boat through the water?
Here are some useful designing steps and formulae for low-power boats:
1. Determine the boat’s water speed requirement, V. This is very application-specific – for a boat intended to tool around a large indoor swimming pool, it can be miniscule. For a commercial vessel where time is money, it can be pretty high. For a boat intended for a stream or costal ocean, it must be at least as fast as the current or tide, or it will be good only for one-way trips.
2. At this point, you can determine how long you boat needs to be at the waterline (LOW), $L = \left( \frac{V}{C} \right)^2$, where C is a “magic” number known as the speed/length ratio. In the traditional English units of knots and feet, C=1.34. In MKS units, it’s 1.13.

For example, if you’re boat must go 2 m/s, it need be only about 3.2 m LOW. To go 3 m/s, it must be about 7 m LOW.

The “magic” of the speed/length ratio has to do with wave propagation speed. A low-power boat has far to little power to “climb its own bow wave”, or plane, so once it reaches its limiting speed, that’s as fast as it’ll go without a lot more (about 3 times) power.

• Now that you have some idea how long you boat must be, you should be able to determine its mass M (usually called “displacement” in boat design). In addition to the mass of its hull materials, engines, passengers, and everything else in it must be included in this calculation.
• You can now calculate your boat’s required power, $P= K M L$. If you’re using old-fashioned units of tons, feet, and horsepower, K is 1. For MKS, it’s about 0.3687

For example, for a 7 m, 2000 kg boat, you’d need about 5200 W. A stripped-down, single-person 3.2 m boat massing only 150 kg would need only about 180 W – well within the capability of even a non-athlete pedal-spinner.
Note that all this ignores a very important consideration – wind. Minimizing the above-waterline surface area of everything is pretty essential on a low-powered power boat, or it can wind up being unmanageable in a strong wind. This is also a strong design argument to have some wind power of some sort – either a large wind turbine (vertical axis like the Cousteau society’s 32 m Alcyone is a good design), or conventional sails

Any ideas on general design and building are greatly appreciated as well!
Keep it light and make it long. Use a twin-hull catamaran design, for long, thin hulls with good stability. Use a high-efficiency prop, rather than a paddle wheel.

For convincing of the goodness of these suggestions, rent a small 2-person pedal boat, and try getting somewhere in it – these recreation vessels are just that – large toys, not suitable for serious cruising.

Be an excellent mechanic before getting into any sort of open-water conditions with such a boat. Have a rescue plan, and a good radio and/or satellite phone.

Not to rain on your friends preliminary design criteria, but consider not “reinventing the wheel”, and simply building or outfitting a conventional monohull sail boat with an electric auxiliary engine, and the other goodies you describe. If money is no object, or you’re really good high-strength composite designers and fabricators, an exotic multihull can be much faster, though the possibility of catastrophic breakup or capsize remains with these high-performance beasts.

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Ok I am not familiar with ocean travels. #1 Cedar (or any wood) is going to be heavier than something made of aluminum or fiberglass resulting in more power needed to push it around.

I looked into generators for home (diy types). Car alternators take more input power to generate electricity than was acceptable for me. Look into motorcycle generators, they are smaller, they run 12 volt, you can find them at junk yards and swap meets, and motorcycle batteries are smaller.

Another aspect you might want to look into is electric chainsaws or weed wackers for your motor ideas.

Hope this adds something to the idea!

Definitely! Thanks!

It seems that golf cart batteries are well-suited for the task, but I haven't researched the prices (mainly because I'm pretty sure they are pricey).

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Here are some useful designing steps and formulae for low-power boats:
1. Determine the boat’s water speed requirement, V. This is very application-specific – for a boat intended to tool around a large indoor swimming pool, it can be miniscule. For a commercial vessel where time is money, it can be pretty high. For a boat intended for a stream or costal ocean, it must be at least as fast as the current or tide, or it will be good only for one-way trips.
2. At this point, you can determine how long you boat needs to be at the waterline (LOW), $L = left( frac{V}{C} right)^2$, where C is a “magic” number known as the speed/length ratio. In the traditional English units of knots and feet, C=1.34. In MKS units, it’s 1.13. For example, if you’re boat must go 2 m/s, it need be only about 3.2 m LOW. To go 3 m/s, it must be about 7 m LOW.

That's incredibly useful info. (sorry for the outline break ;) )

The “magic” of the speed/length ratio has to do with wave propagation speed. A low-power boat has far to little power to “climb its own bow wave”, or plane, so once it reaches its limiting speed, that’s as fast as it’ll go without a lot more (about 3 times) power.

Once again, great info. Are you a sailor perchance?
Now that you have some idea how long you boat must be, you should be able to determine its mass M (usually called “displacement” in boat design). In addition to the mass of its hull materials, engines, passengers, and everything else in it must be included in this calculation.

Eureka! ;)

You can now calculate your boat’s required power, $P= K M L$. If you’re using old-fashioned units of tons, feet, and horsepower, K is 1. For MKS, it’s about 0.3687

For example, for a 7 m, 2000 kg boat, you’d need about 5200 W. A stripped-down, single-person 3.2 m boat massing only 150 kg would need only about 180 W – well within the capability of even a non-athlete pedal-spinner.
Note that all this ignores a very important consideration – wind. Minimizing the above-waterline surface area of everything is pretty essential on a low-powered power boat, or it can wind up being unmanageable in a strong wind. This is also a strong design argument to have some wind power of some sort – either a large wind turbine (vertical axis like the Cousteau society’s 32 m Alcyone is a good design), or conventional sails

Thanks Craig. :)

Keep it light and make it long. Use a twin-hull catamaran design, for long, thin hulls with good stability. Use a high-efficiency prop, rather than a paddle wheel.

My friend mentioned using a similar design.

For convincing of the goodness of these suggestions, rent a small 2-person pedal boat, and try getting somewhere in it – these recreation vessels are just that – large toys, not suitable for serious cruising.

I've taken a double paddle boat on a lake and in the ocean. It's a very tiresome affair in the ocean, but can be paddled long distances with relative ease in a calm lake or pond.

Be an excellent mechanic before getting into any sort of open-water conditions with such a boat. Have a rescue plan, and a good radio and/or satellite phone.

A radio is essential imo. I don't know of his rescue plans and such, yet.

Not to rain on your friends preliminary design criteria, but consider not “reinventing the wheel”, and simply building or outfitting a conventional monohull sail boat with an electric auxiliary engine, and the other goodies you describe. If money is no object, or you’re really good high-strength composite designers and fabricators, an exotic multihull can be much faster, though the possibility of catastrophic breakup or capsize remains with these high-performance beasts.

I'm going to direct him here and hopefully he'll join in. He started with the idea of a fiberglass frame, but abandoned it because of technicalities and expense.

He wants to build this thing REALLY cheap, but sturdy. A real DIY Viking-mobile.

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That's incredibly useful info.

I should have cited its source: “Designing Small Craft” by John Teale (1976). He’s written several books on the subject – see this google search

This book was a given me on my 16th birthday by an uncle, and avid sailor and boatbuilder who designed small craft for Mossberg, a company best known for shotguns. In the 1950 and 60s, they made a brief foray into boats of various descriptions, their most successful being a line of fiberglass canoes. AFAIK, none of their sailboats were ever sold, but I had access to a couple of my uncle’s prototypes.

Once again, great info. Are you a sailor perchance?
When I can be. :( The old adage about a boat being a hole in the water into which you throw money is one of the truest ever spoken. My largest and best boat, a 30’ sloop based on a wrecked 26’ one I finished in 1979, I sold less than a year later. Since then, it’s been other people’s boats, and a wonderful little 12.5’ sailing dingy I’ve managed to hang on to since 1974. This last needs a new swivel main sheet cleat (a bump getting it off a car top late this summer) and new wood parts (some invisible or very sneaky bug in Maryland actually eats mahogany, something I’ve not encountered in the several other states I’ve had it), but nothing like the wear and tear and storage and marina fees on a larger one.
He wants to build this thing REALLY cheap, but sturdy. A real DIY Viking-mobile.
For cheap, sturdy, and low-ish build effort, I recommend a hard-chine (no major curves) hulls built of plywood, lumber, and deck screws, then completely covered (inside and out) in fiberglass. Expensive “marine” plywood isn’t necessary – even construction scrap can be used, though not the heavy 3/4" stuff, if you hold any hope of keeping your mass reasonably low - and while I wouldn’t trust them to last a 50+ years, ordinary blue coated deck screws appear to be good for at least 20 of exposure to salt water. Though initially sealed, you can count on some mishap eventually holing the fiberglass and wetting the wood and screws. Unlike the thick, many layer lay-up of a true fiberglass hull, a few layers over wood is almost certain to need an occasional fiberglass repair.

:rolleyes: It goes without saying and can’t be said to often: even when doing fiberglass work as small as minor repairs, mask, glove, and be careful, or you may sorely regret it – improperly handled, fiberglass can make a blood mess of you, outside and in. Doing large work like building an entire boat, change “may” to “will”. If you’ve not already, or even if you have, read a good book on fiberglass fabrication and safety before touching the stuff. :shade:

This sounds like great fun. Please post pictures :hihi:

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Well, my friend lives in Mississippi right now, so I will not be participating in the building. I might be able to get some pictures from him when he starts, but right now he's still in the design phase. I'm sure he'll be happy to hear that you concur with his idea for a wind turbine as I tried to convince him that it would not generate enough electricity to be useful. The last email he sent, he said he had a sketch for the basic design. I'll post that here (with his permission) once I get it.

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Here's the latest info I got from my friend. He says he plans to join the forum tonight, so the discussion should pick up at that point.

I checked some of this stuff out and it is some good info. I read that person who said the paddlewheel is no good, but the system becomes much more complex when I have to change the 'wheel' motion to the rotary prop motion, although I admit that the prop would be better. For starters it's much lighter.

The info on where to get electric motors rocked. I am already on the golf cart thing, but I just don't know about finding junked golf carts. I saw used motors on ebay for around 80 dollars. There might be a golf cart junk yard in Hotlanta.

I am not going to use cedar at this point. I am looking at pvc. I am going to use pvc to make a frame, then rubber coated chicken wire (tool grip stuff) to make the hull. Then I will use some type of material like hyphalon (raft materail) to cover the hull. Then I will put flotation foam in the bottom of the boat, which in sufficient amount will make the boat unsinkable. Also, the hull will be completley wired (with rubber coated steal cable) together and along with the chicken wire will make it virtually imposible for the hull to break apart. Basically the flotation foam will keep the boat afloat so the hulls task then becomes to make the boat slip through the water effieciently and to keep the inside of the boat dry. I am using PVC because it won't corrode and I will seal the pipe, which if the weight ratio is correct should create more bouyancy. This design should be very light.

Also I am going to put some flotation foam on the roof of the boat which should keep it from capsizing in ANY conditions. Drawing to follow.

One reason that I want to go with a water wheel, besides the gearing system to transfer pedal to prop, is the superior performance in very shallow water and the ability to effectively 'change gears' by simply lowering or raising the water wheel in the water. I would like the boat to perform in very shallow water (perhaps less than a foot) so a prop could inhibit that, although I am willing to sacrifice some shallow water performance for efficiency.

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Any ideas on general design and building are greatly appreciated as well!

Hi Freeztar,

Have you given any thought to Ferro Cement?

If you used curved surfaces you can gain much strength with relatively little weight and cost. I have seen Ferro boats built of varying lengths from 18, 25 and 42 foot (trawler), all on the same displacement hull design.

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Hi Freeztar,

Have you given any thought to Ferro Cement?

If you used curved surfaces you can gain much strength with relatively little weight and cost. I have seen Ferro boats built of varying lengths from 18, 25 and 42 foot (trawler), all on the same displacement hull design.

Interesting, I'd never heard of it before. It seems like overkill for a pedal boat, but seems like a great material for making a medium sized "traditional" boat on a budget.

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Interesting, I'd never heard of it before. It seems like overkill for a pedal boat, but seems like a great material for making a medium sized "traditional" boat on a budget.

Hi Freeztar,

Actually you can make a workable dinghy in about 24 hours with some chicken wire, sand, cement and a bit of effort. The following site has plans for a ferro 12 footer.

Small Craft Plans - Benford Design Group

BTW 1888 - First photograph of a concrete canoe

Team UAH - ASCE Concrete Canoe Team at the University of Alabama in Huntsville - 1848 Records

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Hey Freezy! Just to start with an unattested quote, "a boat is a hole in water that one throws money into."

That said, you guys may want to look into this guy's success pedaling a boat in an ocean: >> Man returns from round-the-world pedal boat trip after 13 years | the Daily Mail

On the hull design, the 2 primary types are the planing hull and the displacement hull. Of the 2, the displacement hull is more efficient as the boat does not need to climb up to plane.

There is a 3rd design which is little known but very succesful and worth considering, and it's called a SWATH boat. Small Waterplane Area Twin Hull. Here's some starter links: :hihi: >> SWATH BOAT DESIGN OR SMALL WATERPLANE AREA TWIN HULL DEVELOPMENT AND SOLAR NAVIGATOR WORLD ELECTRIC NAVIGATION CHALLENGE

SWATH Boat Moves

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Hello to all. I am the person building the boat.

I am going to post my preliminary drawing as soon as I can get my scanner to work.

Currently I am planning to build a pvc frame, cover it with chicken wire (for reinforcement), and cover this with plastic fabric. I will put enough flotation foam in the boat to make it float in the event of a hull breach. I will reinforce the pvc with steel cable and connect this to the chicken wire, which I believe will make it virtually impossible for the vessel to break apart. The pvc frame could be broken, but then the wire/cabling would hold the vessel together until it could be repaired.

I have found a material that I want to use for the hull. It is a polyester weave supported waterproof vinyl fabric (18oz) that is used for heavy duty applications like commercial tents. This fabric costs $120 for 10 yards. If anyone knows of a cheaper, more durable material, pls let me know. I am also looking at using some sort of hard plastic to make a skid guard in heavy wear areas of the hull, perhaps something like an frp (suggestions are welcomed here too). Also I believe that if I put flotational foam on the roof of the cabin, that it will make the boat very capsize resistant. If the boat does turn over, then it would simply float on its side momentarily until the weight of the keel rights the boat. This, I believe, will also provide significant thermal shielding from the sun for the roof of the cabin or keep it warmer in cold weather (but it is more intended for tropical climate). I am also going to use outrigger/s to stabilze the boat, and the flotation foam on the roof is a secondary anti-capsize measure, just in case the outrigger/s were to be broken off in severe weather. I am thinking about using two outriggers that can be taken off the boat and connected to make a catamaran lifeboat just in case something were to happen to the main vessel. Furthermore, I am hoping that I can use the outriggers to lift the boat further out of the water, giving me enhanced shallow water performance, but the outriggers can be lifted out of the water to make the boat thinner in case I want to navigate a very narrow waterway. I have pretty much decided to ditch the paddlewheel idea since I have found something that I think will work better. I intend to use a right angle gearbox with double output shaft (1:1 ratio) to turn an axle that will then turn a prop. I do want the prop to be adjustable for beaching and shallow water navigation. However, I do want to switch between pedal power and electric, and I have to figure out what is the best way to do this. I do intend to carry a generous battery bank on the boat. In fact, I intend to use the batteries as balast. I want to be able to charge the batteries from pedal power, pv cells, and a vertical 'sail turbine' that I intend to build for the roof of the cabin. I am not interested in making a regular sail for the boat because I don't want to have to constantly monitor and adjust sails. I want the operation of the boat to be as idiotproof as possible. I want the boat to have a very low profile for wind and other reasons, so a sail is way taller than what I would want, and the vertical sail turbine will be removable. BTW, I do expect this vessel to be very lightweight. This will make it vulnerable in high winds; thus part of my strategy to make the boat safe in high winds is to give it a low profile and to deploy a sea anchor in very high winds (if this occurs). The design issues that I have currently are: -What diameter pvc do I need to support the weight of the boat (at the keel)? Of course this does depend on the weight. -I need to be able to determine the boats draft. -How many batteries do I need? I would want to be able to cook (hot plate and toaster oven), distill h20, run climate control (space heater in cooler weather, fan in warm weather), make ice with a portable ice maker, run low voltage lighting at night (I want to use Christmas lights), run exterior headlamps when necessary (and perhaps a strobe to be visible to other vessels), run a computer (desktop) occasionally, run a portable mp3 player over computer (amplified) speakers, and have enough reserve to power the electric engine for 3 days (50 miles per day) or as much as possible (if 150 miles is too much to ask for). I was considering 8-10 batteries (deep cycle if I can afford them). And, what capacity inverter will I need for all this? -What horsepower electric engine do I need? I was considering 8hp or so. -Can I configure the electrical system so that the motor that runs the prop can also generate electricity when it is being turned by pedal power, rather than when the batteries are powering the engine? -What is the best way to protect the electrical system from water exposure? Thanks to all for the input. ##### Link to post ##### Share on other sites ;) So many options, so little time. :lol: Before addressing some of those questions, I forgot to mention Alexander Bell's hydroplane as a 4th type of hull design. Not likely for this project, but it's a significant t to cross. NEW HYDROPLANE SHIP.; Prof. Bell Announces Invention That May Break Cr... - Article Preview - The New York Times On the power, Freezy & I have discussed some of the pertinent battery capacity issues over here, starting at post #171: >> http://hypography.com/forums/technology-gadgets/4423-solar-energy-18.html You might look into using one or more commercially available trolling motors and give way the idea of having a direct mechanical link to your pedal system. Trolling Motors & Electric Trolling Motors : Cabelas Nothing about boat equipment is cheap. Last boat I worked on I paid$40 for just 1 quart of marine grade hull paint. Cha-ching! :eek: If you're going in the ocean, all metal fasteners must be stainless steel or marine Naval bronze in order to have any chance against the salt water. There is never a question of if things will fail, but only questions of when. Constant maintenance is required to slow the process.

Looking forward to those designs. :hihi:

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Actually you can make a workable dinghy in about 24 hours with some chicken wire, sand, cement and a bit of effort. The following site has plans for a ferro 12 footer.
Wow, Laurie! That 12’ keel boat is both one of the smallest concrete boats I’ve every seen, and one of the smallest keelboats. I’ve seen quite a few large commercial powerboats with concrete hulls (a builder near my childhood sailing waters cranked out a small fleet of them, local story has it in the 1940s and 50s), but this one’s pretty special.

It’s also very heavy – 391 kg “designed”. My little centerboard boat’s loaded mass is about 150 kg (it’ll sail with 2 or 3 people, but not well with more than 1, and that one best not very heavy). It should go pretty well, having 125 ft^2 of sail, (vs. my boat’s 75, reducible via reefing points), but I’d think twice about at the Benford webpage’s suggestion to convert the design to a centerboard, as I’ve had some exhausting, athletic hiking struggles keeping mine upright for extended periods in serious winds. With a keel, you just sit and smile, let it heel, and trust in the keel to keep things good.

While a good building material for many reasons, I’m reluctant to recommend concrete for a low-power powerboat design, simply because I don’t think you can get it’s mass low enough (though building its internal rebars out of something lighter than steel rod could help).

That said, you guys may want to look into this guy's success pedaling a boat in an ocean: >> Man returns from round-the-world pedal boat trip after 13 years | the Daily Mail
I’d have to say, Jason Lewis’s Moksha, designed by pro naval architect Alan Boswell, seems a better design than I or an army of armatures could come up with. It’s 8 m long, ocean worthy, masses 370 kg empty and 850 fully loaded for an ocean crossing, and can make 3 knots (1.5 m/s) under one man’s pedaling power. She has this very nice design and constuction page, some highlights of which are:
• Built by 2 trained boatbuilders in a year
• Built using “cold molding” of strips of cedar, mahogany, some exotic Ecuadorian hardwoods, and epoxy resin, over throwaway hardwood forms
• Cost about $25,000 • The long prop-shaft drive design with all the bicycle parts had all sorts of problems during the Atlantic crossing (At one point, kept overheating and seizing, and had to be lubricated with dripped cooking oil!), and was replaced with a slightly customized commercial-off-the-shelf one-piece unit intended for recreational pedal boats, ending in a 14” steel prop. She carried 3, and could easily pull and repair or replace the unit from within the boat. Hello to all. I am the person building the boat. Hello and welcome to hypography! Thanks for sharing your very cool project. I have found a material that I want to use for the hull. It is a polyester weave supported waterproof vinyl fabric (18oz) that is used for heavy duty applications like commercial tents. This fabric costs$120 for 10 yards. If anyone knows of a cheaper, more durable material, pls let me know.
Though there’s a lot to be said for working in what you know, I’ve never seen anything like the tent fabric over PVC pipe and chicken wire you describe, and would recommend you give serious thought to something more conventional, like fiberglass cloth. Depending on how many layers you use, this will cost from $1-10/square yard. I am also looking at using some sort of hard plastic to make a skid guard in heavy wear areas of the hull, perhaps something like an frp (suggestions are welcomed here too). You can make practically anything hard and waterproof with epoxy resin – the same stuff I’ve using to cover plywood with fiberglass, and Moksha’s builders used to glue together her cold-molded wood hull. It costs about$50/gallon, has 2 parts that you mix to make harden, and along with fiberglass cloth, can be found on lots of websites and marine stores.
The design issues that I have currently are…
I’ll just answer the easy ones, and the ones I think are most important…
I need to be able to determine the boats draft.
The draft of any boat can be determined taking its mass, calculating the volume of water that masses the same (fresh water masses 1000 kg/m^3, salt a little more, but best calculate everything for fresh water) then taking a drawing of its cross sections at regular intervals, and determining the submerged volume for different waterlines. The draft is just the distance from the waterline to the lowest part of the boat – normally the keel.

-How many batteries do I need? I would want to be able to cook (hot plate and toaster oven), distill h20, run climate control (space heater in cooler weather, fan in warm weather), make ice with a portable ice maker, run low voltage lighting at night (I want to use Christmas lights), run exterior headlamps when necessary (and perhaps a strobe to be visible to other vessels), run a computer (desktop) occasionally, run a portable mp3 player over computer (amplified) speakers, and have enough reserve to power the electric engine for 3 days (50 miles per day) or as much as possible (if 150 miles is too much to ask for). I was considering 8-10 batteries (deep cycle if I can afford them). And, what capacity inverter will I need for all this?

What horsepower electric engine do I need? I was considering 8hp or so.
That’s a lot of power for anything mainly human-powered!

A strong cyclist can typically crank out about 400 W (a bit over 1/2 HP) as long as they have food and water, and give bursts of around 800 W. So, to run an 8 hp motor for 1 hour, you’d need to pedal for 8 hours (or 2 people each pedal 4 hours, etc).

Restating what I said upthread, I’d strongly suggest you reconsider “reinventing the wheel” on oceangoing boats. The problem of man-only long-distance boats was solved many centuries ago, in the form of a sailboat. Though an electric motor is a great auxiliary for getting past windless spells, and confined maneuvering, the seas have practically unlimited of wind power reserves free for the taking. If, like Jason Lewis, you’re determined to set some sort of novel record, best of luck, and hope to help however I can. If you’re goal is just getting from port to port without using fuel, sailboats do that nicely – and are way easier on the legs than pedaling!

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I definitely hear ya about the sailboat having solved these problems, however I have a coulple of problems with it. 1. I don't know how to sail and don't have time to learn. 2. I want a boat that will not break apart, and I know a sailboat can. 3. I want this boat to be super lightweight, and from what I can see sailboats are very heavy.

I saw some recreational pedal boats online that are like 200lbs. Now they don't have the space that I want, but that is light. I want this boat to be the most comfortable thing possible, so I am willing to be educated if something better exists, but it seems to me that sails would be a pain because they require lots of supervision. Though, I don't know much about it.

I am trying to create the best boat that I can for a tight bugdet. I may have 1500-2000 dollars to spend and a month to build it. Considering my circumstances and budget, if I have to buy an aluminum fishing boat, put some oars on it, and cover it with a tarp, then I will do that, but I hope to have something more comfortable.

One thing that I do have on my side is that I am now living in the middle of Katrina's wake, so I imagine that there are a lot of damaged boats and scrap around, and I have seen many boats that don't seem to be in operation. I have even thought of looking in the woods for something that may have washed inland. But, I still am interested in building something custom. It will have to be some sort of alternative design as I understand chicken wire, pvc, and vinyl, but don't understand stitch and glue and fiberglass so well, and I definely don't have 25 large and a year to build.

Fiberglass does seem really appealing, and I am inclined to pick up things fast. I have read some material that makes it sound easy and some stuff that makes it sound difficult and even hazardous.

My premise with this design is to build something out of common materials so that when repairs are needed I can scroung for what I need anywhere in the world for not so much money. I do want the boat to be very safe. From what I understand flotation foam is like magic; it will keep you afloat no matter what. The task then becomes to keep the passenger area of the boat dry and to keep materials from corroding.

The pvc pipe won't corrode. I will coat the chicken wire and all cables with liquid rubber grip. The vinyl tent material that I suggest seems to be very strong and abrasion resistant. I can seal the hull in this stuff so that no water should get in unless the hull is pierced. If the hull is pierced, then I should be able to easily glue or hot weld it.

I have a nack for taking non-standard materials and making something zanny work. I am a survivalist and think in terms of doing things custom and for myself. It seems to me that if I design and build the boat myself that I can better maintain it and repair it.

What I am discussing here is my wish list. I know that I will have to compromise, and perhaps I will have to compromise a lot. However, I would like to have a feather lite, super-strong, unsinkable boat. Concerning my desires for the battery bank, I am willing to be very conservative with energy usage. I will have to cook on the boat, and I insist on having a very reliable way (and a back up) for distilling water. Everything else, including electric propulsion is expendable.

I have an idea for generating electricity that I invite comment on. My idea is to make a four sided sail, four sails in a cross pattern. This should be very simple to make, very light and would rotate in the wind. This could charge the batteries, and I could cook (or use the computer) only when the sail turbine is generating enough energy to support it. But, I want to be energy independent, so I don't want to cook with my kerosene stove or anything like that.

I just read on a website about a gentleman that constructed an electric boat that will do 4 knots for 24 hours with 6 12v deep cycle batteries. This seems approachable to me. I intend to capture energy anywhere I can get it. One of the reasons that I wanted to use the paddlewheel is that I could park the boat on a stream and charge the batteries with the water current. I definitely want to use a prop though since I found this right angle gear box that I believe I can attatch axles to and then turn with bike chains (and there will be 2 pedelers). So I will make a small, light, deployable waterwheel to capture energy from streams to charge the batteries. This won't help me if I'm far away from shore, but at sea there should be plent of wind to move the sail turbine.

I am too new to the forum to post links yet, but when I can I will give links to this gear that I am proposing to use. And I think I have a tight design for the hull, but I have to get this scanner connected.

Thanks again,

T-Diddle

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I was looking over the material about the hpb that circumnavigted the globe. There are some major goal diffenences between what Jason was trying to accomplish in that documentation and what I am trying to accomplish. Firstly, I am not trying to achieve any sort of record. I would like to create a vessel that supports life in an enjoyable way. Secondly, I don't want to have a land basecamp, or work a job on land to support my boating habit. I am attempting to create a coastal survival platform. I would like the boat to be able to cross the ocean, but if it can't then I would be happy to explore US coasts, inland waterways, or whatever, as long as I can get out there and see what is going on in my world, and not just what is going on in my job and on tv. There is so much of our world that is being destroyed before scientists can document it, much less before the everyday man can explore and appreciate it.

A secondary goal that I have is being able to video-document what I see. This is one reason why I would like to have a sophisticated electrical/media/computer system. I don't care how fast the boat moves, as long as it can move consistently. I.e. the boat needs to be able to cut through surf, although how fast doesn't matter. I don't want to carry food for 150 days. I am into survivalism, so I would like to create a survival platform where the boat doesn't need to supply up for long periods. We will fish and gather food as we go. I am into fishing, gathering mollusks, seaweed, et cetera.

My girlfriend and I spent the fall in Maine, and we explored the beaches to the n'th degree...but, it was hard to access many beaches because of local laws, private property, trails that were hidden to outsiders, hostility towards outsiders, et. cetera. So then I decided that we needed a boat. It seems to me that there is a whole other world out there in waterways, islands, et cetera. We seemed to always be looking at a beach across some waterway that we couldn't cross. A good boat would nullify all of that.

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