I have AL80s, HP100s, HP117s, and a brand new HP130. I fit the tank to the dive. For added capacity, I have an AL40 I can sling either as extra capacity or bailout depending on the dive. I have also dived using a HP150, and know people who use them regularly. If sufficient gas volume to do the bottom time is the criteria, there is no need to go to doubles, single tank diving is quite viable. A regularly done local dive sees me using a HP117 and finishing an hour or more later with 1,500psi. I would not use a HP130 or HP150 for that. My son will use a HP100 on the same dive because he doesn't breathe. We like the reserve on those dives. The dive I did with the HP150 was one normally done either as a boat dive or as a shore dive but often with a DPV. We did it as a looooooong swimout shore dive submerged as we were going into the shipping channel. Doubles would not have provided more gas.
Our diving regularly includes wreck diving to 30M on EAN32 with ample gas in our large tanks to make use of our allowed NDL.
Thanks for your reply.
I can see where you're coming from, and I've been through that view and aspect on dive gear myself, too.
As soon as I started diving, I'd get a full kit, and then when it got a bit colder, I'd add a new wetsuit, but as I went deeper I'd need to add a drysuit instead.
As I needed to position myself more effectively, I'd get different fins from those split ones, progressively larger tanks, going from a BCD to a different solution, you name it.
The issue in that was 1) I didn't get to consistently "recycle" what I was learning and how I was diving, which really made things more cumbersome for me, and 2) I ended up with a tonne of gear that I'd end up selling cheap anyway.
Second-hand marketplaces and, particularly, scuba gear vendors generally love this approach.
For a diver though, it's burdensome and costly.
There's also the aspect of redundancy when entering overhead environments. I wouldn't want to be far inside a shipping lane, wreck or cave, turning at my reserve + 1/3 gas and then have a failure on my only tank - particularly if my team member had been skip breathing an even smaller tank all the way, and we now had to contend with increased gas consumption due to stress.
It stands to reason that one single tank failure would probably end up meaning the whole team needing to surface in that shipping lane, and hope for the best.
For me, I ended up with an isolatable solution that simply has 1 AL80 integrated when I dive within the 18m range, 2 AL80s when I dive within 30m range, 2 80s and a 40 for the 50m range, 3 80s and a 40 in the 60m range, etc., progressively adding more tanks integratable with added depth. Same 2 regulators throughout.
Or, add a rebreather component on top of the same base.
Zero waste and 100% consistency throughout the training path, and dives. I think for me, that made my diving a lot easier.
But, as I mention in the video, there are of course more ways to approach both consistency, redundancy and compartmentalization.