The diver gains academic knowledge and skills to enable the:
- Use of decompression software and dive computers to plan and make decompression dives with no more than 10 minutes of total decompression and not deeper than 40 meters/130 feet.
- Use of a single cylinder of decompression gas with up to 50 percent oxygen (EANx50) to add conservatism to the required decompression.
Conservative Decompression:
Tec 40 expands the range of gases available for most Enriched Air Divers from 40% to 50% oxygen content for conservatism during decompression. All dives are planned and executed as if the diver is breathing from back gas for duration of the dive making a single gas switch during decompression. The diver will omit any "accelerated decompression" achieved by switching to a gas with increased oxygen content.
Selecting a Gear Configuration:
Tec 40 allows a range of acceptable gear configurations from simply attaching small cylinders to a recreational BCD through more traditional technical configurations, i.e. back mounted doubles or sidemount. Four acceptable configurations are pictured below - all appropriate for Tec 40. It is wise to consider acceptable configurations for Tec 45/50 when making a selection for Tec 40 as more in-water experience in a specific configuration benefits future training.

The 3-cylinder diagram shows a diver with a single tank and standard valve. This configuration requires a second (smaller) cylinder of back gas to achieve redundant source of back gas and a third (smaller) cylinder is used for decompression gas. The H-valve diagram shows a diver with a single tank for back gas with an H-valve which allows the use of two independent first & second stage regulators providing a redundant method of acquiring back gas with a single decompression cylinder. The doubles diagram shows a diver with back-mounted doubles with independent first and second stage regulators for back gas and a single decompression cylinder. The sidemount diagram shows a sidemount configuration featuring independent cylinders, first and second stage regulators, and a single decompression cylinder.