INTRODUCTIONAs a new diver I remember asking "How long does a tank last underwater?". The answer was "How long is a piece of string?". Well, I still wonder how long a tank will last especially when calculating a dive plan - is there enough air in that cylinder to do the dive safely?
Factors which affect how long a tank will last, include your breathing rate (level of exertion, anxiety, workload, coldness etc). Of course the depth of the dive and time underwater and capacity of the tank will also have a lot to do with it!In the next couple of pages you'll see how to work out your tank capacity and also calculate how long it will last theoretically at different depths. It may seem a little tough going but if you perservere you will be more in control of your diving. You will need a vbscript enabled browser such as Microsoft Internet Explorer, to use the automated calculators..