Hull finish on high speed hull. Polished or Matt?

[Sooty]

Hi

we have a 60mph planing craft.
It currently has a polished Hull.
we are struggling to make the hull quicker.

Someone has just suggested that a mottled finish may be better as it will prevent the hull from "sticking" to the waters surface.

Anyone got any idea's thoughts or better still, experience?

regards
Sooty

[rwatson]

An interesting idea, and not without merit.
A high speed smooth hull can have downward pressure develop - take seaplanes for example, they had to have a stepped hull to ensure breakaway from water on takeoff.
The downward pressure is caused by uninterrupted laminar or streamline flow. Rather than lose speed though friction caused by a total matte surface, maybe just put a few grooves at right angles to the boats direction to disturb the streamline flow - a bit like mini steps, at strategic places.
There are a whole lot of previous discussions on dimpled hull surfaces etc in previous discussions that you might like to look at too.

[Sooty]

Just read articles on dimpled hulls, but your thoughts on steps has just given me an idea to try.

Thanks