-- Last Updated: Dec-02-12 9:20 PM EST --
You'll never ever notice the speed effect
unless you have 100th of a second precision timing
and are in Olympic caliber physical condition.
Generally speaking, a clean smooth hull is good.
People have been playing with smooth vs rough
surfaces for a very long time now.
Myths unfortunately remain in the kayak world.
A micro-grooved adhesive backed plastic film from 3M
was tried out by Greg Barton in the semifinals of the
1986 World Championships in Montreal.
Apparently the grooves need to be very carefully
aligned so they are parallel with the flow of water
over the surface. The size of the grooves was matched
to the density of water and the speed of travel so
that the grooves dampen the turbulence of the water
as the flow detaches from the hull.
This leads up to a popular internet myth
in the kayak world.
The crazy idea of hand sanding scratches lengthwise
down the entire boat hull to make your boat go faster.
Don't do it folks ! You'll never get the robotic
accuracy needed for perfectly straight and parallel
lines down the entire length of your hull.
If you entered the boat in an actual sanctioned race,
you would only get disqualified by the judges anyways.