SS Rosalie Moller [+1941] – A Valuable Lesson Learned

Some say she is the sister ship of the Thistlegorm and in similar circumstances, the SS Rosalie Moller [+1941] was sunk just two days later by the Luftwaffe in October 1941 by a similar raid, following a similar voyage to the Red Sea via South Africa due to enemy navel and airforce control of the Mediterranean in WWII.

On many divers’ Red Sea Bucket Lists, the Rosalie Moller was carrying a cargo of Welsh coal and today lays upright, around 51 metres to the sandy sea bed, 20 metres to her intact mast and 34 metres to the deck. Commented on various websites as “very easy to rack up significant deco” and “a great deep dive for experienced divers only” together with the dive guide stating that his past 5 of 6 attempts to dive this wreck were blown out by poor visibility, adverse wind or tidal conditions, I knew this was going to great dive to stretch my training and comfort levels.

When we arrived at site, there was a good metre or more swell, white horses and there was already another diveboat in situ. Our plan was an early pre-breakfast dive (from the Zodiac again due to adverse surface conditions) to descend to the ship’s deck and whilst others in the group completed their deep diving training, Chris and I would break away to explore the vessel as a buddy pair.

Having investigated the bow and port side of the wreck it was over the deck and into the coal cargo holds, pocketing a couple of lumps from the motherland for posterity and memento as I had decided not to take my camera as I didn’t want it to be a distraction on what indeed turned out to be a big dive. No cheeky deco here, but a true multilevel decompression dive where I wanted to be without distraction.

With 110 bar back gas and 24 minutes into the dive, it was a quick trip to the engine room area and back out. Upon exit, we had been bobbing around between 35 and 45 metres for about 28 minutes and my time to surface (TTS) was 18 minutes, just over my training qualification. But I was happy and comfortable.

However and here’s the rub. After exiting the engine room, I wouldn’t say lost, but with two ascent ropes (one on the bow and one on the stern), we initially picked the wrong ascent line and by the time we got to the correct line, my TTS had shot to 26 minutes. Now some 36 minutes into the dive, these additional 8 minutes bottom time had racked up a parallel 8 minutes TTS decompression obligation while swimming to the bow line at 32 metres. That’s an interesting observation for sure!

With 85% O2 in our decompression cylinders, we could not breathe that until 8 metres and with a 12 and 9 metre stop beforehand, it wasn’t until 49 minutes into the dive that I was able to switch to this decompression gas and ‘hang’ for the remaining 15 minutes at 6 metres.

This was indeed a big dive for me that surpassed my training and past experience. However, what an amazing dive and another first. I have now experienced and appreciate what a 26 minute multilevel accelerated decompression dive feels like and I have some souvenir coals, a big smile and another personal dive achievement to boot. Some great learning too which will invoke additional gas planning thoughts and decompression planning and theory.

• Dive Time: 64 minutes
• Bottom Time: 38 minutes
• Deco Time: 26 minutes
• Maximum Depth: 46.1 metres
• Average Depth: 23.0 metres
• Temperature: 25.3degC
• Visibility: Milky 20 metres