I've decided to go Tech, my Intro to Tech experience

[NothingClever]

If down around 200ft / 60m, consider going a little leaner on oxygen and a little richer on He for the gas density difference.

With 19/30, gas density is 6.2g/l.

With 18/45, it drops to 5.2g/l.

I use Multi-Deco for my DPS so your DPS may show something a little bit different.

 

[Tigerpaw]

If down around 200ft / 60m, consider going a little leaner on oxygen and a little richer on He for the gas density difference.

With 19/30, gas density is 6.2g/l.

With 18/45, it drops to 5.2g/l.

I use Multi-Deco for my DPS so your DPS may show something a little bit different.

Thanks, still working the course but I will keep this in mind and thanks for the recommendation of DPS!

 

[Imla]

I am just a bit curious. If you went through the route of GUE Fundies, why not just do Tech 1 and be Normoxic certified in one class?

 

[sinidive]

Tech 1 is probably more expensive than AN+DP+Trimix(-75) and Tech 1 qualifies for: 51m+30min of deco While TDI trimix for 60m, and TDI trimix-75 for 75m.

Of course Tech1 might have consistently higher quality instruction than places that offer the TDI path on cheap. There are good TDI instructors too of course.

 

[rob.mwpropane]

Still reading/studying ANDP and today I found the answer. With Trimix there are different mixtures for different situations. For me I'm looking at diving to a max of 200ft. So in my case I can breathe air down to 100-130 ft. (I've been to 130 numerous times with no issues)
Once I'm in that range I can switch over to a normoxic mix of 19/30, which will let me go down to as far as 200ft. I'm still reading and am getting more details but thanks for the quick replies. It's so awesome to have come across the answer and to FULLY understand. I'm so excited! Ok I'm getting some eye fatigue so I'm going to take a quick break.

If you can take / switch to Helitrox as someone mentioned. Cost wise it should be about the same. Gas cost would go up some. I think it's good for 35% He in the mix.

 

[Tigerpaw]

I am just a bit curious. If you went through the route of GUE Fundies, why not just do Tech 1 and be Normoxic certified in one class?

Great question, to get a tech pass in GUE you have to use backmounted doubles.

I have back and knee issues and from talking to other divers with the same issues, they informed me that backmount is just too heavy (while on land) so they either go SM or stay single BM.

The weekend I tested for Fundies, I helped my teammates who had doubles and got a chance to see how heavy they were and saw that I had made the right decision. I currently have a Technical Sidemount certification from TDI, so I asked if I could go for a tech pass with SM and was told no. GUE considers sidemount to be an advanced course for the cave divers. Someone had told me they use two 40's to dive BM with and I asked if I could do that because of the weight and I was told no.

As much as I enjoyed the Fundies class I am not about to risk my back and knees just to get a certification. I can continue to practice my buoyancy and finning and do the ANDP courses through TDI and I am happy with that.

 

[Imla]

Great question, to get a tech pass in GUE you have to use backmounted doubles.

I have back and knee issues and from talking to other divers with the same issues, they informed me that backmount is just too heavy (while on land) so they either go SM or stay single BM.

The weekend I tested for Fundies, I helped my teammates who had doubles and got a chance to see how heavy they were and saw that I had made the right decision. I currently have a Technical Sidemount certification from TDI, so I asked if I could go for a tech pass with SM and was told no. GUE considers sidemount to be an advanced course for the cave divers. Someone had told me they use two 40's to dive BM with and I asked if I could do that because of the weight and I was told no.

As much as I enjoyed the Fundies class I am not about to risk my back and knees just to get a certification. I can continue to practice my buoyancy and finning and do the ANDP courses through TDI and I am happy with that.

Nice to get the knowledge though. Just didn't come out in your story that you did fundies in single tank.

 

[rx7diver]

... Someone had told me they use two 40's to dive BM with and I asked if I could do that because of the weight and I was told no. ...

You probably already understand that if you want to dive OC in the 200 fsw range, you will need cylinders larger than double Alum 40's, double LP45's, or double LP50's. So, it's prudent that you train OC with larger cylinders, whether BM or SM.

FWIW, I (at the time 6'2" and 235 lbs) was comfortable making 200 fsw drysuit dives using manifolded HP100's (2 x 35 lbs + gas), which are not crazy heavy full. (I wore an Alum back plate and a weight belt.) Do you think your back and knees can tolerate the weight of manifolded BM HP100's?

If you intend to dive warm water a bit shallower, do you think your back and knees can tolerate manifolded BM Alum 80's (2 x 32 lbs + gas) or manifolded BM old-school 72's (2 x 27 lbs + gas)?

rx7diver