What is the best ski finish?

In other words which is better? Polyurethane or gelcoat? I've read some motor boat sights and it seems to be a debate on which is better. I'm not a chemist and have never owned a boat coated in polyurethane so I know nothing except what I've read. Is polyurethane a good, strong and dependable ski finish?

Polyurethane is microns thick, very tough but being so thin it has no thickness to stop scratches.
Gel-coat is much thicker and can accommodate deep scratches without loosing your waterproof coating, and can be re-finished if need be.
Yes the paint will have a better UV stability but thats about it, all you can do it polish.
If you look after your ski like a baby and touch nothing you can get away with it.