[Sven Osymthe]

I'll check mine in a moment, I think I have 3-5 on windcatcher.

edit:

Pirate is level 15
Windcatcher is level 5

Shiptype - Top Speed / With Full Sail

Light Sloop - 12 / 14 / ?

edit2:

It looks like windcatcher is (noticeably) doing its job. Windcatcher when maxed increases ships speed by 20%.

20% is 1/5th of the regular speed, added to the original.

My light sloop was going 12 knots without any skills. Zep who has no points in windcatcher only managed 10 knots. 20% of 10 would be 2. Add the 2 to the 10, that gives me my current knots. While the Full Sail just adds an extra 20%, or an extra two points (can't really tell from one example).

So given that, I assume that windcatcher does play a role in what our max knots are.