I was there a couple of years ago. It was a multi-family vacation and we had a great time! If you have specific questions about the resort or trip, feel free to pm me.
As for the diving...The shore dives were nice, a bit of current for the newer divers in our group, but completely doable. You get one tank a day for shore dives. I think if you want more they charged $5. You just head down to the dock, pick one up and go!
If you want to do a night dive, pick it up early and put it in your locker. They provide lockers by the dive shop, so head down as soon as you get there and grab one!
They offer a guided shore dive at least once a day and I recommend joining one before heading out on your own. You have to drag a flag so you'll need instructions on where to pick one up and the procedure for entering and exiting the cut. There's a man made breakwater that makes for good snorkeling right off the beach, but to get out to the reef you need to swim out the cut. Just remember to swim WITH the surge
You can book boat dives through the on site dive op. It was a little more expensive than what I'm used to paying, but since this was a family vacation (not a dive vacation) us divers were limited to one day away from the family. It was pretty much a cattle boat, but the reefs were spectacular, especially the Mushrooms! If you've been to Bonaire, you'll recognize that it's the same reef system, but don't expect the same amount of sea life.
There are a number of other dive ops on the island and I've heard really great things about the dive bus. If you have the time, desire and can pull yourself away from relaxing by the beach you should be able to get some great diving in!
