: I have become a little bit interestd in boat design after playing around with
: Ross Leidy's KayakFoundary and have been gradually learning more and more
: as I tweak my design for a competitive ocean/surf ski. More recently, i
: have been reading up on drag. This topic got me thinking about surface
: finish. Typically we aim for a hull finish that is as smooth as possible.
: Why not, it looks good and shows off the timber.
: Then i started thinking about the hi tech swimsuits that are worn nowadays.
: speedo's design team came up with the idea of emulating sharkskin. A
: Sharks skin consists of tiny raked back teeth like thingos called
: denticles which are believed to reduce turbulance directly next to the
: sharks skin.

: I imagine it would be difficult to reproduce sharklike denticles with the ROS
: but was wondering if anybody out there had any insights into the effects
: of surface finish on drag reduction?

: more of an academic question really as I am a mid field plonker so this type
: of fine tuned performance enhancement would be lost on me plus I like
: shint wood.
: Cheers, Craig

I go back to sailboat racing experience, generally find that a slightly roughened surface, actually like a mat painted surface, tends to have slightly less drag than a polished one. Usually obtained by sanding with like 320 - 400 grit sanded wet.

Dolphins also have a odd skin that gives to allow better flow, impossible to duplicate though.

Bill H.