Movement works like this: All ships take their 1st move, check for collisions. Then all ships take their 2nd move, check for collisions, etc.
Backing Sails was unfortunately not programed into this version of the game, so a ship can not "wait" for another to clear.
So a ship's relative speed has nothing to do w/ it.
Oh, yes, and drifting happens after ALL ships have moved.

I hope that helps.

Derek