Accelerated Decompression Procedures (ADP)

Accelerated Decompression Procedures (ADP) introduces a qualified nitrox diver to the use of oxygen-rich decompression mixes to achieve optimum off-gassing at deco stops, and promotes self-reliance within buddy diving.

To enrol on the Accelerated Decompression Procedures Diver course you must have already successfully completed a BSAC Sport Diver course with a 35m depth certification and nitrox training (or have equivalent certification from another recognised training agency). You also need to have successfully demonstrated buoyancy and trim to Gold standard (+ 0.5 m).

You should also have 20 or more logged dives as a Sports Diver, including depth experience to 30m.

You will learn to plan and conduct dives using nitrox mixes with up to 80 per cent oxygen as a deco gas, using a stage cylinder, and you will practise the skills needed to become a more self-reliant diver.

You will develop your knowledge of accelerated decompression diving, including:

• Diving physics and physiology
• Kit configuration to achieve redundancy and self-reliance
• Using the BSAC Ox-stop tables
• Practical stage-cylinder diving techniques, including regulator switching, and run-time management
• Dive profile planning for more adventurous diving, including gas selection and run-time schedules

The Accelerated Decompression Procedures course includes four theory sessions, a dry practical session, and a dive-planning session. It also includes a sheltered-water lesson, and two open-water dives with a total duration of no less than 60 minutes (to a maximum depth of 35m or within your qualification), to ensure that you have plenty of in-water time to practise the skills and discipline needed for accelerated decompression diving.

This is a continually assessed course during which students must reach the required performance standards.

An Accelerated Decompression Procedures diver is competent to plan and conduct open-circuit dives with mandatory decompression using back gas of up to 36 per cent nitrox on BSAC tables, or 50 per cent nitrox using a multi-mix programmable dive computer, and deco gases of up to 80 per cent nitrox, to accelerate decompression, within the depth limits of their diver certification.

An Advanced Twin-set Diver is defined as a qualified Sports Diver who has successfully completed Twin-set Diver and Accelerated Decompression Procedures. They can plan and conduct dives to an extended maximum depth as defined by the current maximum air or nitrox depth limit recommended by BSAC, currently 40m, using breathing gases that they are certified for.

You could do this course at a regional event or local club. Not all clubs run ADP courses, so please check if you are interested.

Alternatively, book your place on a scheduled ADP course online now.

Not a BSAC member? You can do this course by joining BSAC directly or joining via a local club. Find a club.

Students will be given a pack of supporting learning materials. You will need full open-water dive kit suitable for local conditions with either a single or a twin-cylinder configuration and an oxygen-clean deco gas (stage) cylinder with a minimum capacity of three litres and dedicated oxygen-clean regulator. You will also need additional redundant buoyancy provision – such as a drysuit and BC, or a double-bladder BC – and an appropriate configuration of long second-stage hoses.