My rebreather activities have lead me to encounters and to take interest in various subjects wish to share with you, here.

"- 150 meters à Rangiroa : account of unusual dive"

On September 21st 2007, an unusual dive took place in the Avatoru pass, in Rangiroa, French Polynesia.

This dive, -150m deep, is the outcome of several months of efforts by a diving instructor based in Rangiroa for five years, Patrick PLANTARD. Crazy about diving, biology and photography and also of rebreathers. Patrick initiated a long time ago the steps which would bring him below -100m, safely, here, in Rangiroa. He first trained on Buddy Evolution with Penny Glover, then acquired a lot of experience travelling for hours the length and breadth of the bottom of the Tiputa pass, without making any bubbles! He then underwent training with Aldo Ferrucci in Cavallaire, Trimix diluent diving and Evolution air diluent Instruction,to come back, more motivated than ever, to Polynesia in May 2006. He starts offering training courses in Rangiroa, of course, but also in Tahiti and Rurutu, and dicides to ask Aldo Ferrucci to come to Rangiroa for the Evolution trimix diluent instructor course. To do so, he looks for a pupil who would be rebreather diver and trimix diver. Will one of my dreams come true? A diving instructor as well, arrived on the atoll a year before, I have indeed been trained on Inspiration in Mayotte and to trimix diving in open circuit. For me, the rebreather adventure then starts in Rangiroa in November 2006.

During the following months, Patrick carries on setting up his project: he buys a second rebreather- a Megalodon-, an helium analyser, deco tanks, regulators and orders a helium B50 in Tahiti. Personnally, I keep on practising and gaining experience. My days off are dedicated to CCR diving. During all this time, as I don't have a rebreather myself and as Patrick then only have owns one, I am to follow open circuit groups of divers, Patrick's at first, then my colleagues from the six Passengers. I must say there are still bubbles around.… These dive give me the opportunity of great encounters-aaaaah! the impression of being a spotted eagle ray (Aetobatis narinari) when you are in the middle of 60 rays flying ! but particulary to appreciate the decommpression which is optimized compared with open circuit. The Tiputa pass is in fact a site where it is interesting to go down 50m because it's the location where the star of Rangiroa waters can be come across, I have named the GREAT HAMMERHEAD SHARK (Sphyrna mokarran) . The closed circiut allowed me to enjoy fully the Hammerhead plateau, as I remained at the bottom when the bubblers already had to go back up!!! All this in the same diving time...

By the end of January 2007, Aldo lands in Rangiroa, loaded with equipment, his Megalodon, his VR3s... The first week in February is entirely dedicated to rebreather diving. Air diluent first for Patrick's training and mine,then trimix dives in the Tiputa and Avatoru passes. A new world opens up: lunar scenery, magnificient relief, a much scarcer fauna but how interesting. During all these dives, Aldo and I enjoy the presence of silvertip sharks (Carcharinus albimarginatus), sharks which can usually only be observed when they are attracted by food. I relish the sight and am glad to find new anti feeding arguments: if you want to see these animals you just have to go and find then in the zones where they naturlly evolve!!! Patrick, as for him, focused on the reef, can't believe to see at these depths fish whose existence was ignored in Rangiroa, such as the evocative (Centropyge narcosis ) and even fish he doesn't know.

After Aldo's departure, naturally, the adventure continues. We both dive, Patrick on Megalodon and I on Evolution. Patrick has invested on a camera and a housing and our dives then have two aims: the pursuit of depth at times and photo shooting in shallower dives. The latter to -110m part of the training and experimenting of deeper dives. With that number of hours underwater, we multiply the encounters of course, and the absence of bubbles makes us live unforgettable moments. Apart from the lunar scenery and the fauna specific to deeper space, we are still in Rangiroa and it is therefore common for a Manta ray (Manta birostris) or Great Hammerhead shark to come and see us at the bottom... Our pleasure is increased by the temperature and clearness of the waters in Rangiroa. Leaving behind my wetsuit and light, I dive in shorts and without a light. Progressively, we are nearing our common goal : -150m.

On September 20th, we dive to adjust the equipment down to -110m. Hydratation and rest and on the morning of the 21st, here we go! We meet at Patrick's, last adjustments out of the water, launching of the boat, we pick up a sailor and get equipped: the rebreather, the two blocks on Patrick's small boat under the tropical sun, it is tough! At last we are ready: 1, 2, 3, splash! A quick Buddy check and down we go. Fast down to -100m (4 minutes only). Reaching 100m, we slow down a little and get into a fault spotted during a former dive. I look up and it is magnificent: light blue with swirling sharks. If we look down, it's darker and darker. We go down our narrows and here we are: we pass -125m. A big thermocline and I keep on concentrating on everything: the computer, the PPO2, is OK, the scenery, magnificent, the temperature, it's cool!!! The computer, the PPO2, Patrick, the scenery, oh an albimarginatus. In a few words a moment of pure happiness, a mixture of pleasure and concentation. We reach -150 at 7 min 30, which leaves us 2 min 30. Astounding scenery, at -150, the slope changes from scree to a wall shaping a balcony. I bend over, it's all black and I can only make out the white dots of the ’albimarginatus swiming around a few meters below. I have a new look at the computers. Maximum depth 150.8, already 9 min 30 have gone by, the computer announces a total length of 104 min to go up. I wink at Patrick and here we go up. Tonic to 120 and an astounding feeling of coming home when we are at 120m !!! Brief bearings on the computers and we keep on upwards. After seventeen minutes, we reach 100m, wich makes thirteen min beyond 100m. First decompression stop at 101m, twenty-first minute, we are at 75. Thirtieth minute, 35 m and then the computer indicates a total time of 122 min to go up. It was planned. 122 min for deco stop, it's super long, well, it is the price to pay. And, as a special treat, a great Hammerhead comes to greet us during the stop. Lots and lots of emotions. Concerning the pursuit of detph, that's how far we'll go with this kind of equipment and the next dives will be dedicated again to the search for Patrick's mystery fish!

Special thanks to Aldo for his coming in February, to the Six Passengers team (www.the6passengers.com) who had then received us, to the Raie Manta Club(raiemantaclub.free.fr ) who have somtimes welcome us when we were desperately looking for sailor and ENORMOUS thanks to Patrick whose enthusiasm and passion have made these dives possible.

If you also wish to enjoy the logistics by Patrick, he offers Evolution and Megalodon courses all year long in Polynesia and can welcome divers who are already qualified to organize stays and rebreather dives in Rangiroa. You can contact him at the following address : patrickplantard@planeterecycleur.com.

Yann PAYOUX (ypayoux@yahoo.fr)