wetbehindtheear once bubbled...
i would second tom's first three. well worth it.
but do confirm that the boat you will be on can do 2 dives leaving at 9 and return by 1 or 1:30 at the latest. i went out on a boat that shall remain nameless, and it was the slowest thing i've ever been on. Seriously, a canoe woulda given this thing a run for it's money. we were supposed to leave at 9:00, but didn't leave until 9:45 as the "captains" were having breakfast, and then we got passed by EVERY BOAT on the water on the way out to the dive sites and back. We got back at 5:30!!!!!!!!!!!!!!!!
And the "captain" ran into one of the docks while trying to moor the boat in the marina (the one girl told the other to "stop" and she yelled back "it's in neutral" about 2 seconds before the bang. it might have even been funny if it hadn't been an 8 hour day.
but definitely the three tom recommended.