Stage Diving

When divers get full cave certified and start exploring passages that were previously off-limits involving complex navigation, they eventually hit a wall. Not a literal wall of rock, but a strict limit on penetration. Even with increased experience, comfort, and large capacity cylinders, like HP133s, you can only go so far on the rule of thirds. That’s when it’s time to add stage cylinders.

Stage cylinders are independent tanks, typically Aluminum 80s, that are breathed first and then dropped in the cave once a predetermined turn pressure is reached. They are later retrieved and breathed again during the exit.

The Benefits

Obviously, the primary benefit of stage cylinders is range; they allow much further penetration into the system. The strategy is that, by dropping the bottles along the way, the penalty of excess drag is felt only while you are actively carrying them. Once stowed on the line, you return to a streamlined profile. It is the natural progression for cave divers who want to see more of the system.

The Drawbacks

However, stage cave diving is not all positive.

Stages get us much further into the cave, which means any emergency or gear failure must be solved far away from home. While accurate gas planning is a requirement for all overhead diving, improperly managing a stage can leave you deep in a system with low gas reserves. The dangerous tendency for untrained divers is to use the stage like back-gas—breathing a simple third and dropping it. This is ineffective planning. Because a stage is a non-redundant gas source, advanced reserves must be used to ensure you and a teammate can safely exit if a primary gas delivery system fails deep in the cave.

They also increase drag on the entrance. Pushing an extra cylinder against high flow increases your work of breathing and elevated gas consumption, sometimes offering diminishing returns for your penetration distance if your swim technique isn’t perfectly dialed in.

Furthermore, stages require perfect buoyancy control during the doffing and donning portions of the dive. Bottle placement is critical; you must avoid damaging delicate cave structures or impeding the path of other dive teams. Finally, task loading is significantly increased. Managing an extra cylinder while simultaneously handling reels, maintaining complex navigation, or executing an emergency gas-sharing drill requires a high level of skill.

Full Cave+Stage?

Stages can be integrated into a Full Cave program by extending the course length. This is the preferred way to learn stage dive planning and execution for several strategic reasons:

  • Momentum: By the end of your Full Cave training, your buoyancy, trim, and awareness are the sharpest they have ever been. Adding the stage bottle while you are already “in the zone” allows you to integrate the physical skills seamlessly without breaking habit.

  • Logistics: You are already at the dive site with your gear dialed in and your instructor focused on your progression. Combining the classes saves you a return trip, double travel expenses, and additional gear rental fees, allowing you to emerge as a fully capable diver ready to utilize these tools on your own time.

If you have questions on using stages to extend your dives inside caves or taking a full cave program, reach out to me.