Trimix Diver Student Workbook - by Tom Mount and Kevin Gurr. A detailed workbook that addresses concerns, safe dive skills and practical & theoretical knowledge to ensure maximum safety on Trimix dives. Specialized dive planning, planning equivalent narcosis depth, identifying the correct PO2 for various depth from 1.2-1.5 PO2 combined with new waterproof charts (available as an add-on from IANTD), takes the guess work out of mix selection. This is an unparalleled approach to Trimix diving.