A broken dive computer?

Fortunately, diving with the table in the pocket of your vest and a watch on your wrist is a thing of the past. We are all now learning to do it with a computer, but how well do divers know that computer? Not too good in my experience unfortunately. I’ll tell you a story of an American guy who did the north route of the Red Sea with me.

The diving deck

It was sometime in May a few years ago and the weather was fantastic. You know it, a lovely spring breeze pregnant with the upcoming summer with beautiful blue skies. We live aboard that week sailing the north route, known for its many wrecks, including the world famous Thistlegorm. And that wreck attracts a lot of divers every year, including Bob from the United States. Bob was fairly new to diving with his Advanced certification and somewhere in the first 20 dives, so very new. He had bought new equipment just before leaving for Egypt and couldn’t wait to use it. But because he was quite inexperienced and wanted to go out on his own with a buddy, we found him an experienced diver, Richard. Both men got along very well, Richard was happy to share his knowledge as a diving instructor and Bob was hanging on his every word, a wonderful combination. And so they dived together on the famous wrecks, such as the Carnatic, Ghannis D and Chrisola K of Abu Nuhas, after which we continued to the famous Dunraven west of Ras Mohamed. To do a few dives in Ras from there and then move on to Thistlegorm, which Bob was so looking forward to.

Motorbikes on SS Thistlegorm

But during the Dunraven dive, Bob made a crucial mistake that resulted in him missing all 3 planned dives on ‘the Thistle’. Dunraven is a beauty of a wreck, completely taken over by the reef at a depth of about thirty meters. She lies belly-up so there are a number of swimming possibilities. The current has free rein in the immediate vicinity, which means that a lot of food is supplied and life on and around the wreck can be simply fantastic. From the most beautiful corals to large schools of fish, turtles and if you are lucky even dolphins. We were parked around the corner behind a reef and took the zodiac to visit ‘the Raven’. And the current was great as we rolled back into the water and descended to 29 meters. The dive was fantastic, beautiful light, large schools of fish in and around the wreck and we even found some Spanish dancers breeding right next to ‘the Raven’, so it was very busy. Bob and Richard had enjoyed themselves immensely and sat on the sundeck after the dive to discuss the dive with the other guests. At the time, they were still unsuspecting, although Bob had already made the crucial mistake and right under Richard’s nose. But unfortunately mistakes often do not come alone and Bob surely was not lucky this trip.

Reefs & Wrecks route

After Dunraven there was a night dive that both men skipped to enjoy a drink on the deck. Bob, in particular, was full of his experience thus far and eagerly awaited the next day. The plan was to make two dives on Ras Mohamed and then visit Thistlegorm, it was a dream he expected to come true soon. And so the next day arrived and with great expectations we made our first dive on Shark and Yolanda in the National Park of Ras Mohamed. The current was howling and huge schools of trevallies were chasing, large tunas and the occasional gray row shark just before we went into the lagoon to enjoy endless feeding on turtles, squid and even a school of calemari. Ras Mohamed ‘has done it again’, what a top location.

The atmosphere was great when we joined breakfast after the dive and everyone was full of it. After breakfast I desperately needed to do some administration and sat in the salon with my laptop on my lap. Bob and Richard walked past some clothes and stopped at Bob’s gear. She brought in some other divers and it looked like something was up, then Bob came to me and said ‘Anke, I think my computer is broken’, what? ‘Let me see’, I yelled as we walked to his set. Bob had an air integrated computer from one of the well known brands and the display said ‘ERROR’. Bob said that the word made him think his new computer was broken and wondered if we could reset it or if he could rent a computer. Well, which is not possible, but sensible is something completely different. I asked him if I had read the computer manual to see what ‘ERROR’ actually means. He hadn’t bothered and didn’t have the manual with him. Oh okay, that’s not smart either, but luckily there is internet and I downloaded one for him.

Hawksbill turtle

If a dive computer is broken, the display will not work, it will hang in a program or something like that. Back to the source and therefore the manual is the first step. And I can tell you that ‘ERROR’ on any dive computer doesn’t mean it’s broken. No, it indicates that the diver has made a critical mistake and that the computer has been blocked for 48 hours. That blockage is intended to keep the diver out of the water and therefore especially not to go diving, resetting or renting another computer is something we cannot do. Most divers who run into this think that this is not all that bad, but nothing could be further from the truth, this error is there for a reason.

Stunning sunset in Egypt

So we looked at the manual together and I went through the numbers from the past dives with him to get an idea where Bob had made the mistake. What’s happed according to the computer? During the Dunraven dive, the men had made a safety stop, but it turned out that Bob had followed Richard with Nitrox with his air on the tank and hadn’t looked closely at his own computer. And so Bob had gone over his no-stop times and had no safety stop but a decompression obligation. By following Richard and not looking closely himself, he had neglected that obligation and gave the computer ‘ERROR’ on the screen. Bob didn’t see that and jumped happily for the Ras Mohamed dive the next day. Once under water he looked at his computer at one point and saw ‘ERROR’, he showed that to Richard who then signaled that he wanted to dive and that was possible on his computer, OOPS!


The problem is not only the missed deco obligation and that they dive on top of that, but Richard as an instructor deliberately dives with a buddy with a problem with his dive computer, which makes him liable, BIG OOPS! So there was nothing I could do but keep Bob out of the water for 48 hours, which saw his dream of diving on the Thistlegorm go up in smoke for now. And since he not only missed a deco stop, but then dived again, the risk of decompression sickness is present, so we started the treatment with oxygen and fluid and we called the helpline of a diving specialist. Fortunately, Bob understood his mistake and always learned to take responsibility and especially to follow his computer. Richard, of course, was also briefly confronted with the facts and learned an interesting lesson. Fortunately Bob did not get decompression sickness and kept his spirits high. A few months later he flew to Egypt again to realize his dream and he really enjoyed the ‘Thistle’, he texted me.

There you go. A dive computer is easy to use and tells you everything you need to know, but then you have to watch and understand what is being said. And yes I know reading a manual is something few people like to do. But at least look at the warnings and their meaning and follow what the computer says at all times. And does he not work or does he give an incomprehensible code? Then stop all diving activities immediately, make an extra long safety stop, never do a reset and then read the manual again.

Live life… Blow bubbles…

Anke Westerlaken