After hearing about the "windcatcher" from another pirate in the game, I admit I was hurt. After all I had invested 4 skill points on the passive skill and was unaware of the true effect it had on my ship. So then I came to POTCO and read this forum...boy were my eyes opened.
I decided to do the "Race" with each of my ships from Tortuga to Devil's Anvil with no extras (ie. full sail etc) and time myself with a stopwatch as I did the race. The first set was with 4 points on windcatcher and then without.
I GOT THE EXACT SAME TIME FOR EACH SET!!!
War Sloop w/WC 45 sec
War Sloop wo/WC 45 sec
War Galleon w/WC 57 Sec
War Galleon wo/WC 57 sec
War Frigate w/WC 50 sec
War Frigate wo/WC 50 sec
So I think it proves the point that WindCatcher does not improve your ships performance at all. Save your skill points and invest them in something else.