@UNDR H2O
Not sure how your trip will touch all 3 islands and the total duration, a week?
Personally, I take the opportunity to dive whenever I can. I have never dived in Aruba but have been to Bonaire and Curacao. In many ways, I find them complimentary rather one is better than the other.
In Curacao, we stayed in the West end and dived with Go West as per
@NetDoc suggestion. The house reef there, Playa Kalki/Alice in Wonderland, is very good, day or night, almost as good a Bari Reef on Bonaire. We enjoyed our boat dives and shore dives very much. The shore dives are a little farther apart, more driving off the main road, but as said, generally have very easy entry/exit, not always true on Bonaire. There is, perhaps, a little more diversity in the sites than on Bonaire. If I'm lucky enough return to Curacao, I would probably try to get in some more adventuresome dives with Bas Harts
BAS HARTS DIVING CURACAO and/or Dive Charter Curacao
Dive Charter Curacao | the most exhilarating scuba diving The East Point North Coast both look very attractive.
We love Bonaire and have spent considerably more time there. They don't call it Shore Diving Capital of the World for no reason. There are so many good sites, some easy, some not. We also enjoyed boat dives to Klein Bonaire. The house reef at Sand Dollar/Den Laman, Bari Reef, is very good, day and night. Diving on the East side is a fun change of pace to the usual sites
Bonaire East Coast Diving - Unforgettable Scuba Dive Vacation Adventure
Whatever you decide to do, it should be a great dive trip
Good diving, Craig