6/7' tender plans?

[steadybrook]

Anybody know a good place to purchase a set of plans for a 6'or 7' lapstrake planked, towable yacht tender?

[DugT]

Take a look at Paul Fisher's Redshank on this page:

http://www.selway-fisher.com/Otherupto10.htm#RE

[Dave Gray]

Joel White's 7'6" Nutshell Pram (http://http://www.woodenboatstore.com/store/prodinfo.asp?number=400-041&variation=&aitem=4&mitem=5)

[Dave Gray]

7'10" Acorn Tender by Ian Oughtred (http://http://www.woodenboatstore.com/store/prodinfo.asp?number=400-087&variation=&aitem=9&mitem=10)

[holzbt]

7' PRECIOUS by W. Atkin (http://www.boat-links.com/Atkinco/Dinks/Precious.html)

6'6" Petey Dink by Atkin (http://www.boat-links.com/Atkinco/Dinks/PeteyDinkCm.html)
This could easily be converted to lapsrake.

[ 10-10-2004, 10:12 PM: Message edited by: holzbt ]

[Andrew Craig-Bennett]

A word of caution.

I recall reading that these very small prams can be lethal. I think I read it here, or perhaps in the WB magazine.

The difficulty arises if you capsize the dinghy.

Normally, if you do this, you right the boat, get round to the stern, bale out some, and flop back in, of course.

With a very little pram, you cannot re-board.

I was so surprised to read this that I tried it, on a nice warm day in shallow water, with a plastic seven footer.

I am glad I chose a nice warm day and shallow water; otherwise, I would not be writing this now. :(

I tried it again with our nine foot glued lapstrake stem dinghy; no problem.

If I could lay my hands on the original piece, I could satisfy myself about what it said, because I fancy there was a proviso about how and where the bouyancy should be located, which is critical.

I pass this on for what it may be worth.

[rbgarr]

Thanks, ACB. Good reminder.

[ion barnes]

I dont know the specifics of the problem, but it cant be any more difficult than reboarding a kayak. I compliment you for experimenting, that more than what most people will do. Its usually dont at the time of the emergency with tragic results. Did you try righting the boat and climbing in while it was foundering and then bailing it out?

[Andrew Craig-Bennett]

It's different to a kayak in that a kayak has a LOT more buoyancy, and, odd as this might sound, a LOT more stability! The tiny dinghy, when swamped, has negligible stability due to free surface.

You just don't have enough bouyancy to give you enough freeboard to reboard without swamping the boat again.

The dinghy that I tried this with was a frozen snot job, with a double skin, and bouyancy consisting of foam between the skins. You have to bale much of the water out whilst still in the water, to do any good. With the 9 footer, this worked well; with the little one, any attempt to climb in again swamped the boat again.

NB be sure your bailer is on a lanyard. DAMHIKT!

[ion barnes]

Only a double skin? I think then its a question of the volume of buoyancy. How much of the hull volume is given to reserve buoyancy? I know its a difficult answer when dealing with a small boat, as it can become almost useless. The difference between a canoe and a kayak is the deck which itself makes the hull a chamber.

The other problem that arises is when a well-meaning soul puts all the floatation in the bottom of the hull, thinking that its out of the way and if needed, it will lift the hull higher only to find the boat impossible to float upright when flooded! Many powerboats have been designed this way and promoted as having a double hull in critical areas. Thats ok if you rip out a piece of the chine, but disasterous if the boat becomes flooded and subsequently rolls over!

My personal preferance is a 2" foam plank fitted under each of the thwarts and under whatever there might be if it has sidedecks.

[Brian Palmer]

I once had a Bolger Elegant Punt. The plans specify a seat that runs fore and aft with solid foam flotation under the seat reaching to the bottom. This seat and foam combined with the midship frame divided the bottom of the boat into four quarters. This is how I built the boat. When I practiced swamping it, I found it was very stable once it was righted and the water allowed to "equalize" among the four quarters. The surface effect was greatly reduced. The water was prevented from sloshing fore and aft and side to side.

I later switched to conventional seats that ran side-to-side and this benefit was completely lost.

So, a small dinghy can be made more stable if swamped by just dividing up the inside to eliminate the free surface effect.

-- Brian