Anyone with rigger experience?

[Propjockey]

I'm putting the finishing touches on an outrigger hydro, and was wondering..............................

The bottom of the front sponsons is flat. Would a single strake down the center of each sponson help to break up surface tension?

How about two strakes, one on each edge of the sponson to create a small tunnel?

Any ideas, suggestions or opinions?

[laxmasta2039]

hey propjockey

i dont do gas, but elec. builds r pretty similar. alot of catamarans are made w/ a strip down the center of the sponsons, which helps them ride better. there are a couple of tunnelhulls like this too. another idea would be to make the strakes a little thicker and make wedges on the front ends of them. this would help ur 'rigger's sponsons get up out of the water quicker. the tunnel idea would be pretty cool, but i dont know abou it's effectiveness. it would probably depend on whether ur sponson tips normally ride lower, touching or in the water, or up high out of the water. i think a tunnel would just weigh them down if ur sponsons usually ride out of the water. just my opinion. tell me what u think.

joe

[Propjockey]

Thanks Lax--

I posed the same question on several other boards, and got a response from a guy that puts a 1/8" square strip down the inside edge of the sponsons...said it helps to get on plane faster.

I'm undecided at this point--still looking for more input.

[laxmasta2039]

cool. u should definitely do it.

[Ron Olson]

What the strips would do in theory would be to keep water off of the insides of the sponsons to reduce friction while going down the straights, increasing speed. It's an old trick used on cats and tunnel boats. If it really works, I don't know.

[laxmasta2039]

you might want to try to come up with something that you can remove without too much work and without causing any damage to the boat. that way you can experiment all you need to. an email buddy of mine, jay turner, said in a construction article for a catamaran that i am finishing currently that if you make the strips wide enough to extend into the tunnel it will throw the water clear of the tunnel walls, reducing friction, and also help to make the boat grab the water in turns. if you decide to go for it, let me know how it does.

joe

[Propjockey]

Someone on another forum suggested 3M auto trim adhesive tape to experiment with different setups. Sticks good, but can be removed.

How far should they extend past the sponson (to the inside)?
Can you 'guesstimate' a good width to start with? The sponson bottom is 1-1/2" wide and 9-1/2" long.

[laxmasta2039]

my boat is 25", and they stick in 1/8". but then again, the sponsons on a cat are much larger than those on a rigger, so i wouldn't do more that 1/2". the auto tape sounds like a great idea. i would start the wedges about where the sponsons start curving up sharply. just keep in mind that what ur trying to create is flat "ride pads" for the boat to skim along the water on. im not sure if ur boat has those little back sponsons, but if it does, and the boat seems to ride on those also, then u should give them wedges too. good luck, keep me informed.

joe