Fountains come with a pad. In fact that was Reggie's claim to fame for a while when he first started out - a pad keel with a notched transom. (Then he added steps later on.) I'm not sure what your friend did to improve a Fountain race hull, but it had all of the above right from the factory.

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All Fountains do not come with pads nether of the Fountains he races came with a pad. He had to do some work to the bottom of his hull so he said he went aread and put the pad on it to.

Which boat was or is his cause probably 99% of Fountains out there have a pad?

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this is the one he put the pad on

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This is the other one he's not the owner of this one but he throttles it, and i did not see a pad on this one either.

Remember, one of the reasons for adding a pad to a classic (no steps) v-hull was to get it up and riding on the pad. With the advent of ventilated bottoms (stepped bottoms), manufacturers learned some hard lessons about the back half of their hulls. Many early stepped hulls were simply "too well ventilated" and would spin out with little or no warning.

Reggie Fountain went through many generations of steps before arriving at today's designs. These newer hulls do not rely on a pad to get speed, but instead the aeration provided by the steps. Hence, a classic pad on a stepped hull is generally not desirable. Could you add one and gain some speed? Maybe. Could you also totally screw up the handling? Maybe.

I actually have that degree in hydrodynamics (Master's), and am a practicing Naval Architect. I have done plenty of tank and full scale test work, and am sort of handy with composites, and would not venture to try to put a pad on my own Cigarette, although the thought has crossed my mind before.

The problem is that all the mathematics in the world don't really help here. It really comes down to fine details, and you really just have to do a lot of testing to get it right. Without the experience with the particular hull, you are going to end up investing a lot before you get it right. Your pad might end up adding hook to the hull, which might end up costing you more speed than it gains. Also the interaction between the pad and the spray rails might become and issue.

Many of the Fountains with pads have to have trim tab ram spacers to limit how far you can raise them so that they don't chinewalk. That tells me that even they didn't get it quite right.

I'd estimate getting a pad on properly, fairing, prepping and painting would wind up costing thousands in epoxy, glass, filler, primer, and paints, x however many iterations until you got it right, plus 50-100 hours of crappy work under the boat unless you could de-rig it to at least turn it on its side. I say keep your day job, and spend the $20k on some superchargers.

Also, there is the consideration that if your boat is ever involved in any kind of accident where the boat's handling or steering ability is a factor, and it comes up that the hull has been modified, that is going to cause you a lot more trouble with insurance than just having some big motors.