Attacking a ship
Before i attack a ship I try to position my ship on the right hand side of the ship i am about to attack, prior to hitting the attack key.

When i get to the battle screen i always find my ship accurately in position on the right side just as i left it when i hit the attack key.

This gives me the following advantages.
I already have my ship side-on to fire my canon (useful if i am using a war galleon, those things turn slow).
I have the wind at my back when i want to move around or if i want to board the other ship.

More on head swirlies (http://forums.civfanatics.com/showthread.php?t=108946)

Just can't keep morale up (some great research by bigchief) (http://forums.civfanatics.com/showthread.php?t=109053)

Way to go.

As a rule of thumb, attacking from the right or east is always better:

Has someone ever seen the wind blowing in another direction on the Spanish Main? :)