In this case recently reported to DAN AP, divers are stranded in open water when a drift dive doesn’t go according to plan.
In a scheduled series of dives between a charter boat and a dive boat, things started well, but not everything went according to plan. Conditions on the first dive of the day included a swift current with excellent visibility and on the second dive, a drift dive, five divers between the ages of 30 and 70 took off in the late afternoon. Another diver and I decided to not participate in the second dive; instead we remained on the charter boat. The plan for the drift dive included the dive boat taking the divers to the dive site and the charter boat remaining stationary.
The captain of the dive boat accompanied the divers as dive-master, and a designated crew-member remained aboard the dive boat to monitor and retrieve the divers after they surfaced. Post-dive, the dive boat was expected to return the divers to the charter boat. However, the dive boat experienced complications when the prop was fouled and he was unable to follow the divers while they drifted. It took the crew-member a significant amount of time to cut the line and free the prop, so he was not able to simultaneously monitor the divers. By the time the dive boat was mobile again, he was not able to locate the divers. He did not let the charter boat captain know about the delayed status of the dive boat.
Meanwhile, the divers surfaced with no boat in sight. It is estimated the divers drifted a few kilometres from the entry point. One diver had an inflatable signalling sausage, but the crewmember on the dive boat did not notice it. The dive group decided to swim for 45 minutes until they reached the shore of a deserted island. They had no means of communicating to any boats or calling for help. Having no communication from the dive boat, the charter captain felt the divers were long overdue returning to the boat; using a smaller console boat, he began to search for them. He eventually found and retrieved the entire dive party approximately one hour after they reached the shore. Other than exhaustion, the divers experienced no injuries or health complications following this incident.
Thorough predive planning for a worst-case scenario may seem excessive; however, this case shows the benefit of critically discussing and reviewing dive operation plans. Details disregarded as minor may be crucial in the case of an emergency situation. In reviewing this incident, diver monitoring, communication protocols and diver preparedness are three areas in which this dive operation plan could have been improved.
Drift diving from a boat is when divers ride the current through a dive site and, instead of swimming to the boat upon surfacing, are followed and picked up at the conclusion of the dive. Following the bubbles of divers can be an effective monitoring plan; however, a more dependable way to monitor drift divers is to utilise a float line. This method requires a diver to tow a line and a surface marker, which usually consists of a float with an attached diver-down flag. The surface marker provides a more noticeable reference of the diver’s location to the boat operator than bubbles, especially in rough waters.
The diver reported ideal diving conditions; even so, a surface marker could have provided a better reference point than bubbles alone, especially as the dive boat crewmember was distracted with freeing the boat prop. It is unknown if there were any other crewmembers or “bubble watchers” aboard the dive boat. It is helpful to have more than one person observing from topside to ensure the location of the divers is known.
An important detail in this incident is the failure of communication between the two boats. Had the charter boat been notified of the mishap with the dive boat’s prop, the charter boat captain could have provided assistance sooner, potentially preventing the divers from being stranded and having to swim 45 minutes to shore. It is unknown why communication between the two boats failed. Just as dive buddies need to ensure effective communication via hand signals, dive boat operators should also maintain effective communication devices and protocols when dive planning.
The preparedness of the divers should also be considered. The diver reported a safety sausage was deployed once the divers realised the boat was nowhere in sight. Unfortunately, the safety sausage went unnoticed, and the divers had no other signalling devices available. Visual signalling devices should be large enough and a bright colour to be noticed from afar. To be prepared for various scenarios, it is recommended to have a variety of signalling devices available while diving.
Being stranded at sea is psychologically taxing as well as physically demanding. Hazardous marine life encounters, dehydration, exhaustion and hypothermia are all possible life-threatening scenarios. This case serves as a reminder that thorough dive operations planning and thoughtful consideration to details can have a big impact on the safety of a dive.
For more diving health and safety information visit ‘Diving Safety’ at danap.org.
By DAN’s Brittany Trout