Originally posted by Caspian:

Yes! A sailboat will move fastest on a beam reach, I believe, when the wind is going perpendicular across the ship. A broad reach is also pretty fast, when the wind is coming from behind, but from an angle (maybe 45 degrees like you mentioned!), and so the opposite of tacking (tacking is beating upwind -zig-zagging into the wind- if you didn't already know), is called "Jibing", when you stay in that broad reach zone to get the maximum amount of speed.