Originally Posted by scubawife
Usually only applies if you choose to dive with one of the larger, resort based dive ops. The smaller dive ops tend to allow you to dive based on your computer and air consumption, and also give you a longer SI (often at the beach). They're often not back earlier enough to load up the boat again for an afternoon trip.
Not saying you can't do 3 or 4 tanks with a smaller op, just that you shouldn't book with them expecting to be able to do that daily unless you have a group chartering the boat and setting your own schedule.
I didn't find this to be a problem at my DS on Coz. If I let them know I wanted to do 3 or 4 dives a day thye put me on an early morning boat and a late afternoon boat. It paid to let them know up front what I wanted to do.
Sure, if you are with a larger operator who has multiple boats scheduled like this. What I said was that if you are using a small operator (small meaning one or two boat shop), which would be more then half the dive ops on the island, it's harder to get afternoon dives since they don't run on a tight schedule or have a set daily afternoon departure.