The 6 Passengers French Polynesia
The Six Passengers is the best overall dive operator in Rangiroa in my opinion. It delivers top results on every level including personal service, safety, equipment, guides, location, and boats. I have been diving with the Six Passengers on multiple occasions over the past seven years, so I am confident that they are consistent with these details.
The Six Passengers is located beachfront just a few minutes from most resorts on Rangiroa and they will pick you up and drop you back off at your resort for no charge. Their shop is very large with 3 separate rooms including a video room and place to store your belongings. They also have a large deck with several comfy chairs and lounge chairs which you can relax on between dives while enjoying the view of Rangiroa's spectacular multi-hued turquoise lagoon. They offer top-of-the-line scuba gear and have a limited number of Nitrox tanks they can fill. They also have two large bathrooms with showers in addition to the showers located outside on the deck. There are large rinse containers for your gear in addition to a hose. Finally, they have 2 small zodiac boats for 6 passengers each and 1 large boat for 12 passengers.
The Six Passengers does a great job of placing divers of similar ability into separate groups and limits their groups to 5-6 divers per guide. They offer dives at 4 times per day (8:00am, 10:30am, 2:00pm, and 4:30pm, approximately). The dives are timed around the tides and the currents. You can do up to 3 dives per day due to the depth and difficulty of some of the dives. The final dive of the day around 4:30pm is the "sunset dive" which gives the opportunity to see some fish reproduction. All of their guides are experienced, professional, and give complete briefings before every dive.
Dives are centered around two passes: Tiputa and Avatoru. Dives are done with either an incoming or outgoing current and depending on the current, may be into the passes or around the outside of the passes. Big animals and large marine life are seen here so wide angle photography is going to be your focus. Typical marine life includes sharks of various species, bottlenose dolphins, schools of barracuda, large tuna, eagle rays, and manta rays. A highlight of diving Avatoru Pass is the silvertip sharks and for Tiputa Pass is the bottlenose dolphins.
The only category the Six Passengers does not get 5 stars is "overall value" and that is because all diving in French Polynesia is quite expensive. You won't find cheaper diving elsewhere. Expect to pay around 6800 cfp per dive and you can get a package deal with a total of 10 dives which makes the price per dive a bit cheaper.