Combining a passion for diving with backgrounds in maths and a working knowledge of spreadsheets, we at TFM Engineering have created various tools to help with dive and gas planning.  Some of them are here - we hope you find them useful!

OC/CCR Trimix Calculation Tool: Enter multiple rows of depth and mix to allow comparison of CCR loop composition/END, and bailout OC partial pressure/END.  Sure, your Shearwater will do it, but only one gas at a time, which is really painful if you want to compare your options.