WORKING AS A MATE ON DIVE BOATS for the past 22 years has allowed me to be a part of many interesting situations. When teaching scuba classes, I use one particular situation as evidence of the importance of maintaining skills through regular practice. It illustrates that there is no room for complacency in diving.
The day started uneventfully with the passengers boarding the vessel and making the necessary preparations to dive. We cast off the lines and headed to a World War II shipwreck that rests in shallow water (approximately 20 metres deep) off the North Carolina coast. Visibility is typically between 6 and 9 metres. Commercial dive operators don’t normally visit the wreck because of its small size and the potential for limited visibility. All the divers on board had been on the boat before and were familiar with the crew, boat, and wreck.
That day it was my turn to “tie in” while the other crewman assisted the captain with getting the divers in the water. After the captain maneuvered the boat over the site, he gave me the “go” signal, and I stepped off the deck with the anchor in hand. During the brief descent I noticed that visibility was between 4 and 6 metres, which was well within expectations for the site.
Once I secured the anchor to the wreck, I relayed the tie-in location and the dive conditions topside through the wireless communication system. In addition to reporting the visibility, I advised the captain that there was minimal current and no surge. After completing that portion of my duties, I was free to explore the wreck.
During my dive I encountered several of our passengers enjoying their dive. Because of the wreck’s relatively small footprint, it would be quite unusual for a second boat to anchor on the site. As my no-decompression limit approached, I made my way back to the anchor location and prepared to begin my ascent. When I tie in, I usually pause on my ascent to check the status of the other divers. I know what their approximate dive time will be, and I can tell by the bubble trail if any divers are approaching the anchor or have begun their ascent.
While stopped at 9 metres, I noticed two divers were ascending the anchor line and rapidly approaching my position. As soon as they came into view it was apparent that they were dealing with an out-of-air situation. It was a father and son buddy team, and the father was sharing his octopus with the son. Both divers were breathing heavily and moving with a purpose.
I immediately descended and made contact with the buddy team. At that moment the donor’s gas supply ran out. We were about 12 metres underwater, and I had two divers who needed gas.
Knowing that the father was more experienced, I offered my octopus to the son and took one breath from my primary second stage. With my hands occupied holding onto the team and my primary regulator, I couldn’t signal my intentions to the father. He could tell his son was breathing from my octopus and that I was prepared to share my primary regulator.
After removing his now useless regulator, he switched to my primary second stage and took his first breath from my equipment. While I continued to exhale, I allowed the father to take several more breaths before giving a gentle tug on my primary. After taking another breath, the father allowed me to momentarily take back the second stage for two breaths. We quickly established a two-on, two-off rhythm for buddy breathing while maintaining contact with the son.
Once our breathing cycle normalized, I checked my gas supply. I dive with tanks that are larger than I need in case of situations like this. The 15-litre tanks were more than adequate to supply us with gas, even after making a no-decompression dive myself.
When both divers were comfortable and breathing normally, I had to get them from our current position to the hang line and the “hang regulators,” which are used in situations where a diver is low on or out of gas and still needs to complete a safety stop or decompression stop. The first stage is attached to a tank on board the vessel with the second stage at the end of a weighted 9-metre low-pressure hose.
Both divers returned my thumbs-up signal, and we began to ascend again. The son continued to breathe from my octopus, while the father and I maintained the two-on, two-off buddy-breathing sequence. We arrived at the bridle weight and traveled toward the hang regulators at the stern. The boat was configured with a hang regulator on each side, so the divers relinquished my second stage and began to breathe from the suspended regulators.
While they finished their precautionary stop, I maintained a position that allowed me to keep visual contact with them while being close enough to intervene if necessary. The divers finished their stop without further incident and were able to board the vessel. Once the buddy team was on board, I exited the water and prepared to receive the remaining passengers.
I do not know the circumstances that caused these divers to run low on and out of gas during the dive, but the lesson is to carefully monitor your gauges — a lesson all divers need to hear. Knowing how to share gas, both as a donor and recipient, using a technique other than alternate air source sharing is also crucial. Had the father not been trained in or prepared for buddy breathing, the outcome could have been disastrous.
Get training, practice that training, and think outside the box about how to incorporate your training into different situations.
© Alert Diver — Q4 2022