NSS-CDS Trimix Cave Diver

Trimix Cave Diver Training

NSS-CDS Trimix Cave Diver is for cave divers with a legitimate need to go deeper than entry-level cave training limits while using helium-based breathing gas properly. The official NSS-CDS page explains that using helium-based gas mixtures is essential on deeper cave dives, but that open-water trimix training does not simply transfer to caves. Cave trimix adds precise cave-specific gas planning, decompression beginning before the exit, and emergency decision-making in an overhead environment.

This course is for experienced full Cave Divers or CCR Cave Divers with significant post-certification cave time. NSS-CDS lists a minimum age of 18, full Cave Diver or CCR Cave Diver or equivalent certification, and at least 50 non-training cave dives after initial Cave Diver certification. Students should already have strong cave navigation, decompression awareness, team communication, gas logistics, and realistic self-control before adding trimix depth and cave-decompression consequences.

Training generally takes two days and at least three dives. In High Springs, Florida, Trimix Cave Diver supports divers preparing for deeper cave objectives where narcosis, oxygen exposure, decompression, and exit distance must be planned together. The expected outcome is stronger deep-cave mixed-gas judgment, better helium and decompression planning, cleaner equipment preparation, and a conservative understanding of why deeper cave diving is its own discipline.