Hydroplane

I would like to build a hydroplane that would be able to achieve somewhat of a plane with a 3-5hp motor on the back but be able to accomodate up to a 10hp. If this is possible, does anybody have plans?



If i were to build one from scratch, what type of wood would be best? I would then cover whatever material with a fiberglass sheet and marine epoxy.

 

Gonzo said you need 1 hp for every 40# to get up on a plane, so if your, the motor's and the boat's combined weight is over 200# you probably won't plane with 5 hp.

One of many sources: http://sandypointboatworks.com/hydroplanes.html

This boat empty weighs 120#: http://sandypointboatworks.com/Minimost_sport_hydroplane.html

 

Rob White and Sons have plans and instructions for a 16 foot by 43 inch stripper that claims to plane two adults with 4 horse power. I'd be skeptical if the claim was from someone else. Robb, now deceased, was a most inventive and industrious guy who pretty much proved his claims. In this case I think that the boat will do what they say.

Check this out at www.robbwhite.com

 

https://www.boatdesigns.com/products.asp?dept=366

http://static.e-junkie.com/ej/media/content/43586.jpg

http://www.e-junkie.com/shop/product/43586.php

http://www.thinwaterboats.com/9.html

Think SMALLER

 

I built a 10' racing pram about 15 yr ago, it planed at about 12mph with a 5hp air cooled Sears engine.

 

What was the total weight?

 

I never weighed it, but I would guess about 125#. It was 1/4" plywood. I would post a pic, but it is not on the net.

 

I should have said, "What was the total weight, loaded?".

 

Boat 125#
Outboard 35#
Boy 80#
_________
240#

Again, these are guesses leaning to the heavy side.

 

The MiniMax should plane with 5hp at 10-15mph, depending on your weight. Would be better with 10hp, though.

 

So, you got it to plane with 48# per hp. I can see that happening. My first boat did about 10 mph with a 5 hp sears but I weighed about 142# with 24 sf flat bottom and angular bow to total length of 8 ft. total weight of hull was ??? I don't remember.

 

check this out

www.ccwbra.com/

Relative new class that uses 6 HP Evinrude/Johnson 2 stroke outboards as the only allowable power.

 

There's a whole section of hydro planes here including Minimost, Minimax, etc...
http://www.svensons.com/boat/

 

I have an 18' foot canoe that will plane at 18knots with 2 relatively overweight guys on it. SO that is 160lb for canoe and engine, and about 400 for OW guys. So 560 lb with 5hp.

 

Racing hydroplanes

I've built many c-stock, d-stock,and fe class in the 80's and 90's. The boats must be built light, okume ply & okume sticks. Ply is 1/8" max. C-stock will reach a speed of about 70 mph. The FE or formula E will reach 135. Don't know were to find good plans anymore. I quit racing because the Ins. just got to high. Hope this helps...Michael..