Boat design help please

[dweeze97]

I found a boat design from the 1950s that I want to recreate. The problem is the boat was designed to hold a 15 year old, not a full size adult. How can I figure out how much weight the design as is can support and if the boat needs to be enlarged, by how much to support an adult? I know the basic principles of buoyancy and could figure out how much the boat itself weighs but that is where my knowledge of objects that float ends. I also have no idea what the draft of the boat is.

Any pictures, drawings, to make your request a bit clear?

[dweeze97]

http://www.simplicityboats.com/pogo.html

Sorry, the pictures aren't the greatest but that's all I have.

[messabout]

The boat was almost surely contrived by someone who was NOT skilled in the art or science of boat design. Pogo appears to be 72 inches long. I wouldn't let my Labrador Retriever use such a boat and he can swim very well.

Sorry for the outburst but the boat is not a safe one, not even for the 15 year old that you mention. If you want to build a boat like that then simply enlarge it to not less than 8 feet. 10 feet in length would be better still. Were I to build such a boat it would be at least 12 feet in length and 45 inches across the bottom. It would also have some rocker in the bottom so that the transom end would rise to the surface or slightly above. Nothing wrong with the scow type planform for a paddlewheeler. It wont be fast but it might be great fun. Just make it a lot bigger than the plans suggest.

Oh gawd............

I agree with messabout, even on the Retriever!

[PAR]

That boat was designed by a 15 year old boy in the 1950's to have some fun. It's a joke.

Considering your lack of basic understanding in hydrodynamics, I'd strongly urge you to just build something else, preferably not one of these free plans, from over a half a century ago (you get what you pay for generally).

Paddle wheel boats are about as inefficient a drive type as you can ask for, though a novel concept for modern use. Considering the cost of a fairly good, used outboard, you can have a lot more boat and engine (including forward, reverse and neutral gears too) for the same amount of building bother.

If you promise to involve your son and email me privately (click on my name), I'll send you plans for a 12" skiff that you can put a number of propulsion systems on. It's really intended for a small outboard, but other drives can be adapted. This skiff is easy to build from Lowes/Depot materials, will not cost an arm and leg and you can expect it will not drown you half way across the local lake, if you follow the plans.

[Fanie]

Hi Dweeze97,

Sorry about the negative response but I too have to agree You could do better getting a surfboard or canoe. That boat you wanted to build is problems, trust us.

If you are set on building a boat yourself instead of buyng one, do shop around a bit. There are a lot of small and very nifty boats and plans available. These are not difficult or expensive to build.

The first consideration for a boat is safety. You can get some life jackets in the meantime, which I think is the right place to start

To make this a successful project you have to assume nothing is as it seems untill you have verified it with someone reliable and knowledgeable.

This forum has a wealth of knowledge, do read some of the threads. It will also bring a bit of perspective.

[SamSam]

Originally Posted by dweeze97

I found a boat design from the 1950s that I want to recreate. The problem is the boat was designed to hold a 15 year old, not a full size adult. How can I figure out how much weight the design as is can support and if the boat needs to be enlarged, by how much to support an adult? I know the basic principles of buoyancy and could figure out how much the boat itself weighs but that is where my knowledge of objects that float ends. I also have no idea what the draft of the boat is.

The boat you posted is on this site and there are others that might work better.

http://www.svensons.com/boat/

Fresh water weighs 62# a cubic foot (12" x 12" x 12" = 1728 cubic inches)

Without getting too involved and disregarding curves, if that boat you are looking at was a straight sided tub 4' wide and 6' long with sides 1' deep, it would have a volume of 24 cubic feet. If you weighted it down until the gunnels were level with the water, you would displace 24 cubic feet of water which would weigh 1488#. For every inch you displace it would be 124#. That means if the boat itself and the passenger weighed 372#, it would have a draft of 3".