Regarding Rebreathers on Bikini Atoll

Bikini Atoll Divers Notes: Please note that the information below was kindly provided by Jeff Bozanic in 2002. Before reading his article, we would like to add the following updates:

*Because Air Marshalls now uses a Dash 8 to fly to Bikini the weight restrictions are not as harsh. There is now room for excess baggage.

* On Bikini we suggest that each rebreather diver (or at a minimum each buddy team) carry a stage bottle for bailout. If this is done there might not be enough cylinders to go around to be used in place of the cylinders that come with the units.

*Each rebreather diver should bring a stage bottle strap assembly because we do not have many on the island. You will also need a stage bottle regulator for the same reason.

*We typically do NOT have sofnolime on island. If you want to ship the sofnolime to us so we can ship it to Bikini for you, please contact us regarding the 3 Bikini Atoll shipping dates we schedule for the dive season [typically, but not always, we send a supply ship in mid-February, mid-June and early October]. We provide a link to a sofnolime distributor at the end of this article.

*If you are intending on using a rebreather on Bikini you need to ensure you bring cylinders that are appropriate to your unit as we do NOT have any available on Island. We also insist that rebreather divers always carry a bail out cylinder. (We have steel 7litres/45cuft tanks available, incl our hardware.) If you prefer other options then you need to bring them with you. Please ensure your scrubber is shipped as far in advance as you can. We only have a small local aircraft which may struggle with the added weight of the extra supplies required when diving with a rebreather. Please contact us if you have any problems or concerns.

Recommendations by Jeff Bozanic:

I have spent 3 weeks on Bikini Atoll diving on a PRISM Topaz CCR, on 2 different trips. Here's what I have done for those who intend to dive Bikini using a Rebreather:

ABSORBENT: The first trip I carried down 2 kegs of Sofnolime and my CCR as baggage. Total weight was 88 pounds. They only charged me for one container, and I paid US$200 for excess baggage on AMI, nothing on Continental to get to Majuro. I was questioned about travel restrictions on the material (hazardous material questions), but I always fly with the appropriate MSDS for lime, so I could show there are no transport restrictions. I only used one keg the first trip, so I left the second keg for the next trip, which was tentatively planned at the time I left. As a result, I only needed to carry about 5 pounds of lime with me the second time, so I just carried that as well.

For my upcoming trip in July 2002, I shipped lime via postal service to Majuro in time to make the supply boat to Bikini. That only goes 2-3 times per year, so you have to coordinate with Jack Niedenthal's crew on Majuro to make that work properly. I opened one keg, and filled the container to the brim with lime, so I would only have to ship one package. The U.S. Mail only allows 4.5 Kg (10 pounds) of lime to be shipped in a single package, so I covered the plastic container with cardboard, and had no problems mailing it. Cost of postage from where I live in California was US$90, which is much less than AMI charges for excess baggage of US$3/pound.

CYLINDERS: The Topaz is set up to use 19cf aluminum Catalina cylinders. I left those on Majuro (so I would have them when I returned, so I could dive on Majuro), and used cylinders on Bikini. They had 30cf steel pony bottles there [note from Bikini Atoll Divers: we now use 45cf steel ponies], that I used for both oxygen and diluent. They were much longer than the cyls I normally use, but worked OK. Since I was only person diving, they have plenty (I think they had 8-10 of those). If you need more cyls, I would recommend mailing them (empty) as well (2/person), to make the boat. You will be able to carry them back with you, as AMI does not weigh equipment on return, only when going out to Bikini. That way, you only have to mail one way.

GAS: They generate oxygen on the island. The best they could do was 93%. If they have lots of people to do, I would count on 88-90%. This poses two problems: (1) calibration, and (2) not pure O2. On the calibration issue, I set my sensors to read 90% with the loop fully flushed with "oxygen." The electronics would then read properly when I set set point (I do not think that is an issue with KISS system, but I am not sure). With not having pure O2 in O2 cyl, you end up adding some inert gas every time "oxygen" is added to the loop. This is, in essence, now a semi-closed CCR, not a true fully closed CCR. However, the gas volumes are small enough to make this a minor issue, and I just expected to get very occasional gas burps from excess volume in the C/Ls, which is what happened. The Generators may concentrate argon in the resulting gas to as high as 5%. This could be a problem with inert gas calculations. As far as the argon went, I ignored it. I did extend my required deco times to add a margin of safety, but this also was no problem, as my required deco was over usually 30-45 minutes before the OC divers required deco was done. Essentially, I just did the same deco time as the OC divers, and used the extra time as a safety margin.

I used air as diluent. I thought about bringing helium, but with average depths being only 120-140fsw (36-42msw), it was not worth the effort to me. Max depths were usually less than 165fsw (50msw), so even that was OK from my standpoint on narcosis. (I have about 300 hours on CCRs, so was not concerned with the task loading of using equipment at depth). Helium is available on Majuro (I saw several 240cf cylinders in the grocery store, used for filling baloons), but I do not know how they get it there. I think it is shipped from Guam. The problem is, you need someone on island to arrange it, and I do not think I would trust anyone there enough to do so.

UNIT: I use a Topaz, as mentioned, which I stripped on unnecessary stuff before I left. This included cylinders, weight pockets, spare clips and D-rings, etc. Everything on it I didn't absolutely need came off. This dropped the weight to about 25 pounds, which wasn't too bad to ship. As mentioned, I left all of this in Majuro, so that I could put unit back together there, and dive on Majuro as well (has some fun tech diving, see my article in the Summer 2002 issue (v.7n.2) of Immersed). I also left all of the normal filling adapters I carry there as well.

GENERAL: Carry all of the tools and supplies you need to work on units to Bikini. Tools were limited, and silicone grease is even in short supply. The staff there was VERY helpful, but they just do not have much in the way of resources. If you are diving with a group of divers using rebreathers, you might want to ship one set of tools out to make the boat in advance, and then just share them among everyone once there.

If you have any questions, please contact me at JBozanic@HQonline.net.

Bikini can be reached at bikini@ntamar.net or saratoga@ntamar.net.

Hope this helps.

Best Regards, Jeff

	Click here to order Jeffrey E. Bozanic's book, MASTERING REBREATHERS, from amazon.com.
Important Links	FOR SHIPPING OF REBREATHER SUPPLIES TO BIKINI ATOLL: Marine Horizons Contact: info@marinehorizons.com

Dive Tourism Page of the Bikini Atoll web site.

View pictures of our dive, dining and recreational facilities.

Go to the Bikini Atoll Online Store to purchase Bikini dive program T-shirts from our U.S. based secure server.

Return to Bikini Atoll Web Site Main Page