Sea Kayaks Techniques Bulletin Board

Re: severely scratched hull, speed?

Posted By: Nick Schade
Date: Friday, 27 October 2000, at 9:56 a.m.

In Response To: Re: severely scratched hull, speed? (Commonstriped)

The dimples in a golf ball work in combination with the spin to give the ball lift, thus a longer flight. The increased drag is made up for by the higher flight.

Adding surface structure to boat hulls to reduce drag has been tried and works theoretically, but the structure needs to be aligned with the flow. If the boat does not go absolutly straight the structure does not help and most kayaks rarely go perfectly straight.

Some whitewater play boats have patterns sculpted into the bottom. These boats are trying to plane while surfing and the pattern is supposed to help break the suction like the steps on a planing speedboat. This may or may not work. It would be very slow on a sea kayak.

I am not advocating sanding down your hull after every landing, or doing anything else about it, but if you want to know if scratches add drag, the answer is "yes". They add drag and the addition can be quite significant.

: I mentioned this once a while back, a cyclist [maybe Lance Armstrong] wore
: this all rubber body suit thing that had ripples [about 1/16 to 1/8 high]
: along the entire seam that seperated the front of the suit from the back.
: Apparently, this helps to break the suction of the cyclist passing through
: the wind. A small achievement shaving fractions of seconds off his
: "time". I think a golf ball is bumpy for the same reason... tho
: this is no reason to take a ballpeen hammer to your hull. I think those
: dimpels also help impart spin... to hell with the golf game tho, I think
: the only place those scratches are causing drag is in your ego.

: Relax.

: Pete

Messages In This Thread

severely scratched hull, speed?
MT -- Tuesday, 24 October 2000, at 10:23 p.m.

Re: severely scratched hull, speed?
M. Hamilton -- Tuesday, 24 October 2000, at 11:39 p.m.

Re: severely scratched hull, speed?
Tim Smith -- Wednesday, 25 October 2000, at 12:36 a.m.

Re: severely scratched hull, speed (affectation)?
Tom Dowling -- Wednesday, 25 October 2000, at 12:45 a.m.

Based on what?
Brian Nystrom -- Wednesday, 25 October 2000, at 10:18 a.m.

Spd Reduction Due 2 Scratched Hull, Based on what?
Tom Dowling -- Wednesday, 25 October 2000, at 10:34 a.m.

Re: severely scratched hull, speed?
Nick Schade -- Wednesday, 25 October 2000, at 10:10 a.m.

i think you guys are tilting at windmills - - -
dan -- Wednesday, 25 October 2000, at 8:39 p.m.

Re: i think you guys are tilting at windmills - -
Steve -- Wednesday, 25 October 2000, at 9:13 p.m.

Re: i think you guys are tilting at windmills - -
TomBrooklyn -- Thursday, 26 October 2000, at 9:26 a.m.

Re: fishing tools answer
Mark -- Sunday, 29 October 2000, at 8:18 a.m.

Re: i think you guys are tilting at windmills - -
Steve -- Monday, 30 October 2000, at 11:01 p.m.

Re: i think you guys are tilting at windmills - -
Nick Schade -- Thursday, 26 October 2000, at 9:48 a.m.

Re:Is this the real Dan Quixote?? *NM*
Ian Johnston -- Sunday, 29 October 2000, at 12:33 a.m.

nah .. he was impractical
dan -- Sunday, 29 October 2000, at 6:45 a.m.

Re: severely scratched hull, speed?
Lee -- Wednesday, 25 October 2000, at 11:55 p.m.

Re: severely scratched hull, speed?
Jack L -- Thursday, 26 October 2000, at 3:03 p.m.

Re: severely scratched hull, speed?
dave mcadoo -- Thursday, 26 October 2000, at 3:06 p.m.

Re: severely scratched hull, speed?
Jack L -- Wednesday, 1 November 2000, at 7:34 a.m.

Re: no,no,no
Lee -- Thursday, 2 November 2000, at 12:14 a.m.

Re: severely scratched hull, speed?
Commonstriped -- Thursday, 26 October 2000, at 3:10 p.m.

Re: severely scratched hull, speed?
Nick Schade -- Friday, 27 October 2000, at 9:56 a.m.

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