Do I need to make a reservation in advance to dive the morning after arrival, since we don't get in until 8:30pm?
What about the checkout dive? Will we be on the schedule before we arrive? Thanks

The check out is first and then boat diving. All reservations have to be made in person... Ron

When you arrive ask about what time the orintation
for diving is the next AM. It is usually around 9-10 am by the dive shop. I think the dive shop opens around 8am.
I would check in with them and fill out the paper work, get your park tag and keys to your locker and weights right after breakfeast. Bring your C-card, a credit card and passport with you.
Then go back to the room and get everythingelse you need to dive with, put your cards and passport back in the safe(you won't need them again to dive) and go back for the orinentation talk.The dive shop is not that far from any of the rooms.
The check out dive is right out front on Calabass reef. ( I think it is free)and it is one of my favorites.
Go to the left and past the small sunken boat a little ways(almost 1/2 way) and look out in the deep for the tarpon. They will swim right past you!
Under the Divi docks,especially the south one, there are lots of different fish too. Great snorkel spot.
On your way back to the steps,look for the octopus under the dive shack, ask someone. It hides in one of the empty metal cylynders. Look for the pieces of coral it may have at the entrance. It comes out sometimes in the late afternoon.
Then you can sign up of the afternoon boat dive too,if you like.
Have fun!