Using A Pony Bottle On A Decompression Scuba Dive

In relation to my Suite articles on Alternate Scuba Regulators and how to use them, I’ll recount a story of when I saw an alternate effectively.

It was a number of years ago when I dived on the wreck of the President Coolidge in Vanuatu.

This was a United States ocean liner that ran into one of the US’s own mines while entering Santo Harbour during World War Two. A few thousand troops were on board.

The captain ran the ship aground in the harbour and the vast majority of the troops got off safely. The ship eventually slipped back underwater making it a great dive spot!

It is a deep dive and all the precautions are needed to prevent the Bends. Generally, only experienced divers should attempt this dive.

When I dived this site, the divemaster used a pony bottle on every dive. This is a fully duplicated scuba system, including a small tank.

He said that another second stage wasn’t any use if he was stuck in the bowels of the ship at 50 metres and the first stage failed!

On a deep decompression dive one of our group did run out of air just before the ascent. She was just on the verge of panic at around 30 metres, when it was an easy matter to use the divemaster’s pony bottle for the ascent to the spare tank at the first decompression stop.

This was a great example of having a full duplicated system for the ultimate in safety.