Help With Economical Semi-Planing Designs

brian eiland said:

Thanks Tad, I've got to get my copier working correctly so I can enlarge that card and study it.

Wave slap at stern?
I don't know if it has been mentioned in this subject thread, but I do remember seeing a reference to the reverse deadrise hulls of the SRD hulls 'slapping' at the water surface when their sterns were rolled out of the water on either side.

Anyone experienced this firsthand??

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Yes, if I understand what you are referring to. A chine or other appendage on the side of he boat that that has a down transverse angle and contacts the water will do this. I think the principle reason is that forward motion causes water to enter the opening of the overhang and slaps against the hull when it reaches the end. Air trapped in the slot also has an effect but I'm not sure of the details. Shannon's SRD would be similar and larger so probably louder.

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