We dove last year on Raiatea with the dive operator who is just to the left of the dock in Fare as you look out to the water. Both dives were outside that pass, one was not so good because the current was too strong-we opted out of a second dive that day because we were too tired. Next day's dive was superb!
I take my own full length wet suit and use it to snorkel as well as dive. I get cold easily and it also is perfect sun protection. My husband has a shortie that he also brings but doesn't wear it as much as I do. We also bring our big split fins and booties, mask and dry snorkel. With the new luggage restrictions, we pack our booze in the suitcase and cram our fins in the carryons.
If the ship is stopping at Rangiroa, the diving there is absolutely perfect. We have dived with Six Passengers and also with the outfit that is based at the Kia Ora hotel. Both are good, speak English, and are safety oriented. The only problem I have is that they dive from big zodiacs and it's darn hard for me to hoist back up into the boat!