Savvy Diver Prevents Uncontrolled Ascent

An experienced diver with an underwater scooter saves an unprepared diver who overbreathed his regulator and attempted an emergency ascent.

Reported Story

I regularly dive with a small group of experienced divers off a privately owned boat. We are part of a group on, and occasionally others join us for a dive. This time a diver with advanced open-water (AOW) certification and about 30 dives joined us for an after-work dive on the Jim Torgerson (RSB-1) wreck, which sits at a depth of 120 fsw (36.6 msw). Visibility was 10–50 feet. The current was strong enough that some divers familiar with this site complained about it. We all wore wetsuits and breathed 32 percent nitrox on open circuit.

The new diver was struggling as he went down along the anchor line with his buddy. I, along with several other divers, followed shortly after. A few minutes into my dive, I heard a rapid tank tapping, and another diver pointed to the new diver ascending from the wreck far from the anchor line. He was buoyant and gaining speed. I was diving with a SS Minnus dive propulsion vehicle (DPV, or underwater scooter) and was able to quickly ascend from 90 fsw to 65 fsw and bring him back to the anchor line at 90 fsw. If I had not grabbed him, he would have done an uncontrolled ascent and surfaced in current, unable to get back to the boat on his own. On the anchor line, other divers came over. We communicated that I’d take him up and that the other divers would finish their dives.

I had him hold at 90 fsw to give him time to settle down and for our bodies to have some time to adjust to the rapid ascent and decent that we had just done. I also had him switch to my long hose in the belief that my high-end regulator would be easier to breathe from as he worked out the CO2 hit. He had about 1000 psi left, but I also wanted to save his gas for getting him back on the boat.

We worked up the anchor line, taking it extra slow and doing an extra-long safety stop before I put him back on his regulator. By the time we were ready to surface from the safety stop he looked much better, although he had thrown up through the regulator during the safety stop. When we made it back on the boat, I made sure there were no medical issues other than seasickness and did a long assessment. I ended my dive with 1515 psi in a HP120 and a full 13 cf bailout bottle.

We agreed that despite his AOW certification and having 30 dives over the past two years, he needed to gain more experience and work his way down to a dive like this gradually. He is prone to seasickness, which was a contributing factor along with poor buoyancy and not wearing gloves. He should have communicated early on when he started to have problems.

Several other divers saw him in distress from the wreck, but neither his dive partner nor any of the other divers could get to him once he started ascending. If not for having a powerful DPV, I would not have been able to do anything either. I took into consideration the fact that I had just started my dive, it was my first dive of the day and that quick ascents deeper than 60 feet are less dangerous than close to the surface. I am a technical diver with about 370 dives AN/deco and studying trimix. I dive wrecks of these depths on an almost weekly basis and am very comfortable in these conditions.


This was a typical case of a diver diving beyond his training and experience. Informal dive groups are likely to overlook this issue because of respect for autonomy and freedom. While each diver is responsible for himself, everybody in the group would be affected in case of a dive accident; thus, divers in the group have the right to check each other’s competency. It is not impolite; it is a part of the safe dive culture.

Buddy systems among divers who are strangers to each other often fail. It happened in this case, too. For the buddy system to work, divers need to establish rules before the dive, be comfortable about the other diver’s skills and agree to a common dive plan. When diving in a strong current such as in this case, a buddy check at surface before descent is often impossible. Thus, it is more important to have a good predive conversation and complete cross-checking.

Another diver in this group most likely saved the life of this inexperienced diver. The rescuer probably would not have succeeded without using the scooter, which enabled him to catch up with the ascending diver before he got too shallow and bring him back to a safe depth. An exerted diver experiencing an emergency ascent often ends up with lung barotrauma, arterial gas embolism and drowning.

Experienced divers in informal groups should not keep to themselves. Instead, they should volunteer their advice for the good of the entire group.

Dr. Petar J. Denoble, MD. D.Sc.