One for the Pot

By Steve Ellott.

Most of you will know that I suffered a bend in July whilst diving from a Hardboat out of Brighton. This article will tell the story of that incident from a personal point of view and will explain what went wrong, and how it was put right.

The day started well, the sun was shining and I was well rested after an early night. I had drunk no alcohol in the previous 24 hours. Having had a good breakfast of eggs and bacon at the Marina cafe I was well set up and raring to go. The first dive was on the Braunton at around 35 metres; a deepish dive. Dive planning discussions with my buddy had led to a dive plan that was to include no more than 10 minutes of stops on the computer. The dive went to plan with stops at 6 metres (8 mins) and 3 metres (2 mins) and no problems. So what next?

The second dive was a reef patch off the marina to a maximum depth of 17 metres after a surface interval of exactly 2 hours. This dive was carried out normally with no stops as we had left the bottom after 30 minutes with time remaining on the computer.

Well pleased with my days diving, I immediately dekitted, packed my gear away and got changed. While doing this, I became aware of a slight pain in my right shoulder. My first reaction was that it was a muscle strain from pulling myself up the latter perhaps, or from some other exertion such as humping kit about. I also remember thinking that "I hope that this is not what I think it might be". A few minutes later the shoulder began to itch and confirmed my worst suspicions. On inspection, my shoulder was a mottled purple colour, and slightly swollen.

We were coming into the marina at this time, and it was decided to go to the local hospital with my buddy and have it inspected before doing anything else. It should be noted that my symptoms at this time were of a skin bend and a slight shoulder niggle. I can remember having the niggle a few times before and never connecting it to decompression illness, but the skin bend looked nasty. The doctor agreed, but had little experience of decompression problems. I decided to phone the Duty Diving Medical Officer at the Institute of Diving Medicine at Alverstoke. He advised me that they could probably sort me out at their chamber if I cared to come down.

On the way to the chamber a further niggle developed in my left elbow (on the other side), the skin bend had gone right across my back, and half way down it. Arriving at the chamber, I was asked about my dive details and then given a neurological examination. The chamber people rarely see skin bends and mine was such a "good" one that they took photographs. Within a short time, I was in the pot and going down to 18 metres on pure oxygen. The pain disappeared at this depth but the skin bend was not fully resolved.

If you remember your lecture on either gas toxicity or nitrox diving you will recall that the maximum partial pressure of oxygen in a mix must not exceed 1.6 Bar partial pressure. This equates to a diving depth of 70 metres (8 bar absolute). When pure oxygen is breathed, the depth must not exceed 1.6 Bar absolute, or 6 metres of depth. Here I am at three times the maximum recommended depth (at 2.8 bar absolute) on pure oxygen expecting an oxygen fit at any moment. For this reason I had to lay very still.

The schedule that I was to follow was Royal Navy table No 61. This table requires all symptoms to be resolved within 10 minutes of starting treatment. My skin bend was not totally resolved, and so a longer stay was required following Royal Navy table No 62.

  • Down to 18 metres on O2
  • 20 minutes on O2
  • 5 minutes on Air
  • 20 minutes on O2
  • 5 minutes on Air
  • 20 minutes on O2
  • 5 minutes on Air
  • up to 9 metres taking 20 minutes on O2
  • 15 minutes on Air while dinner was eaten
  • (Pasty, new potatoes and baked beans!)
  • 60 minutes on O2
  • 15 minutes on air
  • 60 minutes on O2
  • Up to the surface taking 30 minutes on O2
  • Total dive time 4 hours 45 minutes.

It was uncomfortable breathing from the O2 mask as the inhalation and exhalation resistance became very wearing. The mask also cut into the bridge of my nose. Oxygen was not allowed to leak into the chamber atmosphere which was compressed air. If any leak occurred, the chamber operator outside, who was sampling the partial pressure of oxygen in the chamber, would call out the percentage of O2 over the intercom to the attendant inside, requesting that the oxygen mask straps be pulled up tighter, cutting further into an already sore nose.

During the last hour of recompression therapy, the attendant had to breathe O2 as well as he had had the equivalent of a dive to 18 metres for 75 minutes, a 30 minute ascent to 9 metres, and spent 2 hours at 9 metres further loading up his tissues (he didn't want to get bent as well!).

Back at the surface, the doctor gave me a good check over testing for neurological functions once again. He also recommended an overnight stay at the local hospital for observation. In the morning more checks and some advice about diving, tables and computers from a visiting American Diving Doctor. Nick Harley came down to collect me with Ann, but instead of going to RN Hospital Haslar, they went to HM Prison Haslar, and were surprised not to find me there.

I got off very lightly. Diving within my computer I had an incident. The equivalent dive carried out on BS-AC 88 tables requires a 3 minute stop at 6 metres on the second dive, but this is for a square profile - mine wasn't.

So why did it happen? The answer to this question will be discussed in a further article to be published, but I will give you some clues. Over 40, overweight, a smoker, an occasional drinker, a deep dive, a repeat dive, and a short surface interval (perm any 8 from 10).

My thanks to Nick who took me down and recovered me the next day

This page was last updated on : 06 Sep 2011