hull break on hydros,

[paulejr]

how important is the hull break on how a hydro handles ? or is there a formula for deciding where the break should be and is it critical for, say 36" boats vs larger boats, and is the angle for the forward part of the hull critical and if so what angle should it be?

[Fluid]

By “break” I assume you mean the step or sponson transom. What kind of hydro are you talking about? Scale hydros, sport hydros, outriggers, stepped hydros? Some are limited by regulations, some by operation: oval racing, SAWs, sport running.



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[paulejr]

semi scale (?) wood framed hydro (36") tunnel break is about 13 inches forward of the transom, was just wondering if this was near scale or just some stab a sport model. don't know who made the kit or built it. was nitro and i am converting it to FE.

[1coopgt]

Pictures???

[lohring]

I wrote an article on breaks.

Lohring Miller

It's the Breaks.pdf

[paulejr]

Lohring, nice work on the explanation.. here is the foto of my 36" , break at about 12.5" from the transom.
hull break.jpg

[srislash]

Very good info lohring. I’m absorbing what I can in my rediscovered ‘hydro theory’.

Thanks, Shawn

[RandyatBBY]

I know for sure that the entrance of the tunnel must be higher than the tunnel floor at the break point. How much depends on type and size of boat and power of motor. The weaker the motor the farther back and higher it must be to creat lift. If the entrance of the tunnel is too low you will see skuffing and water flying over it and may submerge the boat. If it is too high you will lift the front of the boat and blow over at speeds. The height of tips of the sponsons will keep the boat going when it has to run threw waves at speeds. If not high enough it will not recover. The inclination of the rear of the ride pads are veritable to the power and speeds wanted.