Actual experiences asking boat operators to provide larger or multiple cylinders

[Lorenzoid]

On the liveaboards I have done in the Red Sea, the operators have no issues in renting you a bigger tank (15l) for the week. Given that on both of those I was one of the newest divers and also one of the largest, my air consumption was always going to be above average. The extra size just allowed me to match the dive times of some of the others.

On Red Sea Aggressor my wife and I requested 15l (steel) tanks that were advertised as available on request, and we were told they would try to accommodate the request but could not guarantee it. My interpretation was that they had to get 15l tanks from somewhere else--they do not ordinarily keep 15l tanks on the boat. When we arrived, they had none for us. Two other divers had received 15l steel tanks. But as it turned out, we really didn't feel we needed them. On the deeper dives, we did the deep portions along with everyone else, and we simply poked around the shallows at the end of the dives five minutes or so less than some others. No big deal.

I can see the utility of larger tanks on wreck dives with square profiles, where you want to calculate "rock bottom" volume needed or whatever reserve you wish to plan, but on reef dives, we generally find it easy to adjust our profiles on the fly to make the air last long enough for our satisfaction.

 

[Neilwood]

On Red Sea Aggressor my wife and I requested 15l (steel) tanks that were advertised as available on request, and we were told they would try to accommodate the request but could not guarantee it. My interpretation was that they had to get 15l tanks from somewhere else--they do not ordinarily keep 15l tanks on the boat. When we arrived, they had none for us. Two other divers had received 15l steel tanks. But as it turned out, we really didn't feel we needed them. On the deeper dives, we did the deep portions along with everyone else, and we simply poked around the shallows at the end of the dives five minutes or so less than some others. No big deal.

I can see the utility of larger tanks on wreck dives with square profiles, where you want to calculate "rock bottom" volume needed or whatever reserve you wish to plan, but on reef dives, we generally find it easy to adjust our profiles on the fly to make the air last long enough for our satisfaction.

The boats I was on had a number of 15l tanks available and, unless otherwise booked (which I had at least on the second trip), they were on a first come first served basis. I did find the larger tank useful as, as a relatively new diver, my consumption was higher (especially at the start of the trip) than the more experienced divers who had at 50-100 dives at a minimum. I was also coming off a spell where I hadn't dived for about 3 months due to circumstances.

Based on my consumption at the end of the trip, I might reconsider the requirement for the next one.