Can Crystalline Salt Reduce the Size of Scuba Equipment?

safe diver quiz

A popular article over last few days is one about crystalline salt that can uptake and store oxygen in high concentration. It was published in Chemical Science by Jonas Sundberg and coauthors from University of Southern Denmark.1 The article describes a synthetized crystalline containing cobalt combined with an organic compound, which has some properties of biological carriers of oxygen like iron-based hemoglobin in mammals or similar copper-based carriers in other animals.

The most significant property of this crystalline is that it binds oxygen reversibly – it can uptake oxygen and release it – and that this process may be controlled.  Professor Christine McKenzie, the leader of the team that synthetized the crystalline, told the Science Daily2 that among other applications:  “When the material is saturated with oxygen, it can be compared to an oxygen tank containing pure oxygen under pressure – the difference is that this material can hold three times as much oxygen. This could be valuable for lung patients who today must carry heavy oxygen tanks with them. But also divers may one day be able to leave the oxygen tanks at home and instead get oxygen from this material as it “filters” and concentrates oxygen from surrounding air or water. A few grains contain enough oxygen for one breath, and as the material can absorb oxygen from the water around the diver and supply the diver with it, the diver will not need to bring more than these few grains.”

Validation of Tasmania’s Aquaculture Industry “Yo-Yo” Diving Schedules

Validation of Tasmania photo (3)

Office of Naval Research 2014

While vacationing in Croatia, I heard a story about a diver who fits the description of people I sometimes call “robo-divers.” The story’s hero is a famous Croatian sponge diver, with whom I share an acquaintance. My friend, who is one of his teammates, described this robo-diver’s practice, which is similar to previously described empirical dive practices of other local sponge divers: Reportedly, he does four descents per day to extreme depths, after each of which he ascends very slowly without decompression stops. After the last dive of the day, he quickly takes his boat to shallow waters (within approximately 10 minutes) and descends for about two hours of decompression, split between stops at nine, six and three meters (30, 20 and 10 feet).

I don’t know about his decompression sickness history, but I do know that he is 64 years old now, and the fact that he has survived this long following those types of dive practices make me think of him more as a robot than as a man of flesh and bone. At very least, it is unlikely that this diver has a PFO.


Microparticles and Decompression Stress: Connecting the Dots

blood sample

During the ONR-NAVSEA Progress Review Meeting that took place in Durham from July 15-17 this summer, Stephen Thom summarized the current status of his research on circulating microparticles (MPs), which are small fragments shed by various cells that have been exposed to stress. These MPs can be found in subjects with inflammation or injury and in divers after diving.


DAN at UHMS: A Recap


At the Undersea Hyperbaric Medical Society (UHMS) Annual Scientific Meeting, DAN produced six papers, two collaborative papers and funded two more. With additional five papers from International DAN organizations – DAN contributed approximately one-third of the diving medicine presented at the meeting.

I gave an oral presentation about effectiveness of predive checklists, with Shabbar Ranapurwala, doctoral student in epidemiology at UNC as a first author. The paper is coming, but let me tell you in confidentiality, checklists work, even in diving. It was confirmed in a randomized trial conducted in three dive resorts. Volunteers received either a predive checklist and a postdive report (the intervention group) or the postdive report only (the control group). Divers who received the predive checklist experienced fewer mishaps during the dive than divers who did not receive it. Divers in control group were not prohibited from using their own checklists nor were they reminded to do so. The reduced number of mishaps in the intervention group indicates the effectiveness of predive checklists in prevention of accidents and a value of reminding divers to use it.

To learn more, read “Checklists: Keys to safer diving?”

Post written by:

Petar Denoble, MD, D.Sc.

Dr. Petar Denoble is the Vice President of DAN Medical Research. After graduating from medical school, Dr. Denoble joined the Navy in the former Yugoslavia and specialized in naval and diving medicine. For 13 years he was involved with training, supervision and treatment of divers in open circuit, closed circuit, deep bounce and saturation diving. His doctoral thesis focused on studying oxygen consumption in underwater swimming. He has been at DAN for 20 years where he has been involved in the development of the largest database of exposure and outcomes in recreational diving, the monitoring of diving injuries and the study, treatment and prevention of fatal outcomes and long-term consequences of diving accidents.