Course availability

[bernieflyer]

Is this course still available? I don't see it anymore on iantd's website.

Expedition Trimix Diver
A. Purpose
1. This program is designed to train OC divers already involved in deep diving activities to more safely conduct exploration dives
requiring extended decompression profiles and helium -based gas mixture. This program is not intended to be used as an
enticement to divers who are content to remain in normal Sport or EANx diving limits.
2. Trimix affords a safer means for deep-water exploration for divers who dive deep or perform with a clear head at depth. The
IANTD Trimix Diver Program requires the diver to be self-sufficient/reliant.
3. This program qualifies divers to perform Trimix Dives outside of training up to 400 fsw (120 msw).
B. Prerequisites
1. Must be qualified as an IANTD Trimix Diver or equivalent.
2. Must have at least 100 Trimix dives and 25 Trimix dives to at least 300 fsw (91 msw) or sufficient experience conducting
technical dives to satisfy the instructor that the student has the ability and knowledge to continue into this level of training.
3. Must be a minimum of 21 years of age.

[Jim Wyatt]

Yes it is still a sanctioned IANTD course. You can visit www.iantd.com and do a search in the instructor database to see who is certified to teach it.

[OneBrightGator]

Jim, I couldn't find the OC version in the drop down search list, only CCR.

[bernieflyer]

I`m rather more curious where such dives could be practiced.......hopefully in caves......

[aainslie]

My .02c worth is once you've done 100 Tx dives. it's not clear to me what the advantage is of yet another course.

I recently did a 400 ft dive with a buddy, and we regularly push 300 these days. It takes a bit of planning and it helps to have an in-water backup diver, but I don't really see what a class is going to teach you.

That said, I think you'd be nuts to do 400 ft in a cave without a rebreather!!! You're at 14 atm - at a GOOD sac of 0.5 cfm, you'll go through 1/3 of a stage in 4 minutes!!! If you're nervous (gee, why would anyone be nervous in a cave at 400 ft?), perhaps 2 minutes! So let's see - how long does it take to shout down a stage and deploy the next stage? Probably about 2 minutes... you'll spend the whold dive just changing stages as fast as you can.

Our BT on the 400 ft dive was 4 minutes. That took overfilled double 130's, a tank of 21/35, of 50/20 and of O2, plus contingency cylinders of each of those mixes to be shared between the team. It was quite a mission for a 4 min BT. I decided after that to seriously consider rebrethers if I wanted to get serious about going deep. OC is a serious schlepp at those depths.

[Brian Kakuk]

I think that Andrew is right. CCR really is the safest way to do these dives. I just returned from Andros Island in the Bahamas, and was involved in this very course with a Swedish cave diver and we had a blast. We were both on Megalodon Rebreathers.

The course (either O/C or CCR) is all about gas planning at deeper depths and use of multiple stages (at least 3). Max depth for the course is 400 feet, but you must do at least one dive deeper than 333 feet, with the other required dives to be deeper than 220 feet.

The course was taught in the Bahamas because we could not find enough deep cave training sites to conduct the course in Florida. I would not want to do this course in open water!! I hate long hangs in blue water where I feel like a bait fish! I am sure the wreck divers out there would disagree.

Our deepest dive was conducted by swimming 1100 feet into Guardian Blue Hole at a depth of 170 feet, then descending to a depth of 400 feet down a huge vertical fracture..total time from leaving the surface to ascending to the first stop (320 feet) was 25 minutes. This bottom time and profile exceeded published tables for 8/60 so we cut our own as backups and used two VR-3 dive computers each. We were out of the water in just over 3 hours and 30 minutes. Water temp was a cold 81 degrees at deco.

Other bailout gasses carried or staged in the cave were 20/24, EAN 36 and O2, all at appropriate depths.
The other dives were each around 330 to 380 feet. A lot of in-water time for a course.

Setup and breakdown dives were conducted prior to and after the deep dive in order to establish bailout gas cahes (at least one and a half times the gas required to get one diver out of the cave and through deco).

I did these same dives (during original exploration) on open circuit side mount back in 1992 through 1996 and the gas use was rediculously more for O/C.

I don't think Andrew is correct in saying this is not a worth while course however. I believe it really is if you are moving toward deep exploration cave diving or deep wreck diving(eeewww!). The instructor will also explain and include the use of custom deco software for cutting tables (either O/C or CCR) plus backup/bailout tables and gas and CNS planning.

My 4 cents worth.
Safe diving,
BK

[aainslie]

That's 2c more than me!!

Brian clearly has more experience here. With a good instructor, it might be a good class. We were really just bounce diving - Brian's talking about some serious dives there!

[bernieflyer]

Thanks for those excellent answers. I agree 400ft on OC must be a major hastle. I'm actually more curious about finding sites in the 250 to 350ft range, to gain more experience at my level, and i prefer caves to avoid long decos on a line plus the schlepping tanks on and off the boat.