Next step / possible training to pursue

[tomcatbubba]

To the OP, are you sure you need deco bottles for recreational Trimix? From my understanding of those courses, they are no deco only, and therefore would not require a deco bottle(s) for accelerated decompression. Also, I don't discount the utility of helium in very small amounts for deep recreational dives. My general rule of thumb is that I start using helium around 80 feet, if I can find it (I usually can as I have it at home and work). Other than the benefits for gas narcosis, this article sums up nicely how gas density affects CO2 retention, even at modest depths. Helium having a MUCH lower density than N2 or O2, brings down density very nicely. https://gga.kr/wp-content/uploads/2...-Scientific-Diving-Proceedings-2016-simon.pdf

 

[Marie13]

To the OP, are you sure you need deco bottles for recreational Trimix? From my understanding of those courses, they are no deco only, and therefore would not require a deco bottle(s) for accelerated decompression. Also, I don't discount the utility of helium in very small amounts for deep recreational dives. My general rule of thumb is that I start using helium around 80 feet, if I can find it (I usually can as I have it at home and work). Other than the benefits for gas narcosis, this article sums up nicely how gas density affects CO2 retention, even at modest depths. Helium having a MUCH lower density than N2 or O2, brings down density very nicely. https://gga.kr/wp-content/uploads/2...-Scientific-Diving-Proceedings-2016-simon.pdf

Yes, recreational Trimix, what TDI calls Helitrox (up to 35% He, to 150ft), does require one deco bottle for class. Whether you use one for dives after class is your choice. You have to take Advanced Nitrox before or concurrently with Helitrox. In the midst of this class currently.

 

[tomcatbubba]

Yes, recreational Trimix, what TDI calls Helitrox (up to 35% He, to 150ft), does require one deco bottle for class. Whether you use one for dives after class is your choice. You have to take Advanced Nitrox before or concurrently with Helitrox. In the midst of this class currently.

How about IANTD: Recreational Trimix Diver (OC, SCR, CCR) this is the course I was thinking about. I'm not sure if IANTD still offers it or not.

 

[Marie13]

How about IANTD: Recreational Trimix Diver (OC, SCR, CCR) this is the course I was thinking about. I'm not sure if IANTD still offers it or not.

Are you aware of the current cost of helium, outside of the cheap stuff in FL? I'm in a major metro area in the Midwest and I'm paying $4.60/cft. There are other options that are cheaper but I'd have to drive at least 8 hours roundtrip. Few people are going to do this stuff OC unless they have a cheap source of helium. I doubt helium is cheap given where the OP is located.

 

[tomcatbubba]

Are you aware of the current cost of helium, outside of the cheap stuff in FL? I'm in a major metro area in the Midwest and I'm paying $4.60/cft. There are other options that are cheaper but I'd have to drive at least 8 hours roundtrip. Few people are going to do this stuff OC unless they have a cheap source of helium. I doubt helium is cheap given where the OP is located.

Well aware, both at retail and wholesale, I teach it. Cost to me is somewhat irrelevant. I don't dive deep a ton outside of class, but when I do, sure I'll use light helium in my mix if I can. I get narc'd fairly easily especially on hot drops with feet down descent. And it isn't the nice kind of narcosis, its the dark insidious kind. And I tend to do wrecks where there is current, which means I am swimming hard sometimes, so C02 retention is a problem. So I use helium. My life is worth a few extra dollars to do it properly. This is all based on my situation. YMMV.

Before discounting helium based on cost alone, all factors should be considered. That includes gas density and C02 retention as I mentioned. Read the article if you have time. It should be required reading for technical classes IMO. I always offer it to my students so they are better armed with advanced dive planning factors.

 

[Marie13]

Well aware, both at retail and wholesale, I teach it. Cost to me is somewhat irrelevant. I don't dive deep a ton outside of class, but when I do, sure I'll use light helium in my mix if I can. I get narc'd fairly easily especially on hot drops with feet down descent. And it isn't the nice kind of narcosis, its the dark insidious kind. And I tend to do wrecks where there is current, which means I am swimming hard sometimes, so C02 retention is a problem. So I use helium. My life is worth a few extra dollars to do it properly. This is all based on my situation. YMMV.

Before discounting helium based on cost alone, all factors should be considered. That includes gas density and C02 retention as I mentioned. Read the article if you have time. It should be required reading for technical classes IMO. I always offer it to my students so they are better armed with advanced dive planning factors.

I get narced rather easily myself, which is why I'm just dealing with the cost. We're using 20/20 for class. However, for someone like the OP, who just wants to be a better recreational diver, and from his posts in this thread, is not wanting to spend a ton o'cash, I don't think this would be an option for him. Cost to YOU might be irrelevant, but it's very much something a lot of people take seriously. I paid approximately $380 for the helium for my first two class dives. People here and on FB were up in arms over what I paid. Some have access to cheaper helium and others couldn't conceive of paying that much.

 

[tomcatbubba]

I get narced rather easily myself, which is why I'm just dealing with the cost. We're using 20/20 for class. However, for someone like the OP, who just wants to be a better recreational diver, and from his posts in this thread, is not wanting to spend a ton o'cash, I don't think this would be an option for him. Cost to YOU might be irrelevant, but it's very much something a lot of people take seriously. I paid approximately $380 for the helium for my first two class dives. People here and on FB were up in arms over what I paid. Some have access to cheaper helium and others couldn't conceive of paying that much.

Yes, that is a lot of money. I did say "somewhat" irrelevant. I wouldn't be doing $380 dives on a regular basis. I'd probably be looking for a different dive at that price, unless it was really worth it. I'm doing some really cool, pristine wrecks up in NJ in the fall (possible U boat), I'll likely suck it up for those. Often though, it doesn't take that much helium to bring the END under control. N2 is 1.25g/L density, He is 0.179 g/L. So Nitrogen is about 7 times more dense than He. Density drives up C02 retention under high work load. Even 5 or 10% helium can make a difference in END and density at depth.

 

[Marie13]

Intact wooden schooners from the 1800s trump a U-boat, IMO.

 

[tomcatbubba]

Intact wooden schooners from the 1800s trump a U-boat, IMO.

Indeed. I was supposed to be in Lake Erie next weekend doing some of that but a family vacation to SC put a halt to that.

 

[MichaelMc]

I wouldn't call TDI Helitrox a rec. class, as it goes with the full tech AN/DP. It's just not as deep as full trimix.

IANTD rec trimix is no deco, no second gas and 130' max. It is rather like Nitrox with a big emphasis on a slow ascent rate, and its dives are optional. It has deep and nitrox as prerequisites. I just finished it. Plus RAID has a trimix option within their rec deep, no-deco, class.

(Of course, IANTD advanced rec trimix is in the IANTD tech lite group and includes accelerated deco, so....)

Over kill on learning can be good, particularly when things can go bad.