Dive Time Calculator – This Microsoft Excel spreadsheet will give a theoretical time, based on previous air consumption history, tank size and depth.  It is an approximation for use when planning a dive, but should only be used as estimation.  Output includes a ‘bottom time’ which is a safety factor to ensure 1/3 of the air remains for ascent and emergency use.

Buoyancy Calculator – Buoyancy of a pressure vessel changes as mass (air) inside is used up.  This tool is used to calculate the tendency of a scuba tank to float or sink as the air inside is used up via breathing.  It is useful to determine how much weight you should use when diving with a new tank or in water of varying salinity (salt or fresh water).

Tank Equalisation Calculator – When filling one SCUBA tank from another, the final pressure will depend on relative capacity, pressure and temperature of each tank.  This will calculate the final pressure when both are combined.  It also includes a metric/imperial tank conversion tool.

Nitrox Gas Constant Calculator – Standard ‘air’ is accepted to have a gas constant of 0.287 KJ/Kg-K.  When you alter the oxygen content the gas constant changes.  This spreadsheet was created to calculate the gas constant for Enriched Air Nitrox with oxygen contents other than 20.946%.  This was used in the Tank Equalisation calculator.  There are not many actual uses for this spreadsheet.

Nitrox Blending Calculator – This Microsoft Excel spreadsheet is used for blending Enriched Air Nitrox.  It will calculate the final blend when different concentrations of Nitrox are mixed or will predict the required concentration in order to achieve a particular mix.