SSI Extended Range Cavern Diving eLearning

SSI Extended Range Cavern Diving — eLearning & Certification Credit Only

Take your first step into the world of technical overhead diving with the SSI Extended Range Cavern Diving specialty. This course bridges the gap between recreational and technical cave training, teaching you how to plan and conduct limited-penetration dives within the light zone. This product includes your academic training and certification credit only — the in-water sessions must be completed separately with an authorised SSI Extended Range Instructor.

What you’ll learn online

• SSI overhead environment diving philosophy and progression
• Cavern versus cave diving limits and safety protocols
• Specialised equipment configuration and redundancy setup
• Gas planning, rule of thirds, and emergency reserve calculations
• Line handling, tie-offs, and guideline management techniques
• Team communication, awareness, and lost-line recovery principles
• Light failure management and gas-sharing procedures under stress
• Environmental conservation and responsible cavern exploration

Required practical training (booked separately)

To earn your full certification, you must complete the in-water cavern training dives with an SSI Extended Range Instructor. These dives are designed to apply your theory in real overhead environments, and typically include:

• Guideline setup, tie-offs, and navigation within the light zone
• Simulated lost-line and light-failure drills under limited visibility
• Emergency air-sharing and team exit procedures
• Gas management exercises using the rule of thirds
• Buoyancy, trim, and propulsion techniques to minimise silt disturbance
• Progressive penetration dives while maintaining a clear path to open water

These sessions are not included in this eLearning product and must be booked separately with Dorset Diving or another SSI Extended Range Dive Centre that offers the Extended Range Cavern Diving specialty.

Important prerequisites

• You must be at least 18 years old and certified as an SSI Advanced Open Water Diver (or equivalent).
• A minimum of 24 logged dives is required before starting the practical training.
• Prior experience in Deep Diving and Diver Stress & Rescue is strongly recommended.
• You’ll need a current medical statement and valid first aid/CPR certification before any in-water training.
• Before booking, confirm that your chosen dive centre offers SSI Extended Range Cavern Diving and has appropriate overhead environment sites available.

Free registration

To begin your eLearning, register for a free SSI account and affiliate with our dive centre here:
Register with Dorset Diving.

What’s next?

After completing Extended Range Cavern Diving, you can continue your overhead training with Intro to Cave Diving, Full Cave Diving, or expand your technical diving knowledge through Extended Range Wreck or Technical Extended Range programmes.