Purchasing your first dive computer. A non-technical approach.

[Joneill]

There is a limit on time. How you chose to spend that time is up to you. If you want to spend 5 minutes at 5m or go directly to the surface is your choice. In the dives you posted complaining of running out of NDL at 100ft you could have chosen to split the time differently, spent longer on the interesting part and then done the required stops. If the difference between brand X and brand Y is that brand X gives the stops and brand Y does not then really it does not matter as you will not actually be planning a direct ascent in any case.

I was not complaining about reduced NDL - I was just making the observation. In addition, how I spend my dive time is only up to me within the limits of my training - I am not trained in decompression diving and therefore it would be unwise/irresponsible of me to do what you suggest.

What you are suggesting is that because the brand Y computer is happy about your longer profile then the boat ought to be happy.

I did not say that at all - the boat wants me back on board in 60 minutes max and will be happy if I comply with that rule, regardless of what computer I use.

Consider your GC dive. You ended it after 45 minutes with gas to spare because there was nothing to look at at the depths you could stay at without incurring stops. The way I would do that is plan a total time in the water, within the limits impose by the boat and split the bottom time between that and the stops. Within your 45 minutes you might have left the bottom 10 minutes later and still had 20 minutes to make the ascent. Exactly when to leave the bottom is subject to your actual profiles of the day. Once you start to plan based on a maximum time to surface you get many more ways to run your dive.

I am not trained in decompression diving so I will not do that. I had no issue with the dive and quite enjoyed it - as I've said already, I was just using that as an example of how NDL gets affected after multiple days of deeper and /or longer dives.

Also, use nitrox. At these depths you get 40% longer.

I am nitrox certified, know about the benefits and risks and do dive with it - but I'm not fully comfortable diving it when the bottom for a good portion of the dive is about 4,000 feet past the MOD and there is a chance I'd be bumping up against/past the MOD even on the top of the wall.