Wreck Diving – HMHS Britannic
When I first asked Dave Thomson if he had any advice about diving on HMHS Britannic, he said, “It’s an absolutely fantastic wreck – you’ll love it, but you shouldn’t even consider diving it without a scooter. The current is completely unpredictable, and you don’t know if the direction in the surface is the same as on the wreck and can be so strong that you can hardly hold on to the anchor line.” Needless to say that I equipped my scooter with a new battery with a battery life of over 3 hours, which I had specially made.
Wreck Diving the HMHS Britannic
A normal prerequisite for diving on such deep wrecks is that you dive with a rebreather to obtain a reasonable bottom time as well as a sufficient safety margin if something goes wrong. It is virtually impossible to carry enough gas in the various mixtures to obtain a bottom time of more than 20 min at the depth of the Britannic, not to talk about the bill for Helium and Oxygen, and the logistics to fill bottles If the dives were to be performed on an open system. So, I dive with a rebreather from JJ-CCR, created by Jan Pedersen from Præstø in hand-crafted precision work. It is often referred to as “the 4×4 of the Rebreather community” because it is simple to operate and works according to the so-called KiSS principle and has a reputation for being extremely reliable.
This is not the same as saying that a rebreather is simple to dive. Therefore, the requirements for the participants in the expedition are also somewhat out of the ordinary with the requirement of proof of min. 10 dives over 100 meters and 100 trimix dives. It is necessary when looking at the prerequisites for the dives at Britannic, where the expected total dive-time is estimated at about 3 hours, use of a scooter, 3 bailout cylinders (which are used only in case of failure of the rebreather) as well as a back-up of all essential equipment.
In preparation for the expedition I was for instance on a trip to dive the deep wrecks out of Villasimius in Sardinia (including San Marco on max 107 m) as well as a trip to Arenzano, where we dived on the Amoco Milford Haven (max 84 m) as well as U455 (max 118 m) to be sure the equipment was in order and the configuration and dive plans were up to the challenges.
Since the dive center at Kea, which we used normally is a recreational center, it is necessary to bring almost all the equipment down there including stage bottles. That is why I and my two Belgian colleagues sent a large part of our equipment down there by a truck in two large boxes with a total weight of over 300 kg, in addition to our normal diving equipment of 50-60 kg, which we each carried by plane to Athens.
Preparations for diving HMHS Britannic
Finally arrived in Kea after a long trip by plane, car, and ferry the work begins with the assembly of all the equipment, mixing gases for rebreathers and bail-out cylinders and be sure that all the batteries are charged. The standard bottom gas was a TX 8/70 and as the bailout gases, most of the participants chose to dive with 3 x 12l Alu cylinders with respectively TX 12/60, TX 20/35 and NX 72 as a compromise between the safety and the convenience. At the same time, NX 50 was placed on the anchor line at 21 meter and pure Oxygen at the deco station. Standard dive schedule was 25 min bottom time (incl. descent), giving a total dive of about 3 hours depending on which deco plan is selected.
Then all available weather forecasts were scrutinized to assess when we could get into the water. In general, the wind is required to be below the wind strength 5 (~ 8 m/s) and the wave height less than 1 meter. At the same time, the current in the water above the wreck must normally be less than 1 knot. The three things do that you can usually only dive every 3. Day in October. Fortunately, it looked good with 2 possible dive days immediately after arrival, so there was hectic activity at the dive center.
The first day there was still too much wind to dive on the Britannic and we, therefore, chose to dive on the second wreck included in our permission, namely the passenger line SS Burdigala (183 m long and 20,000 tons), which is upright on 70 m, a little closer to the coast and hence more weather protected. Burdigala is a really nice wreck, which in itself is worth a trip to Kea. It is quite similar to SS Polynesia off Malta but is in much better condition (even if it is in two pieces) as it is subject to the same restrictions as Britannic and is therefore only rarely dived. After a drive of about 2 hours on Burdigala with about 35-40 m visibility, all the equipment, and the configurations had been tested and were ready for the next day.
As the weather looked to improve, the people from the center along with the expedition leader, went out to put the anchor line on the Britannic’s stern near the propellers, while the rest of the participants rehearsed their patience and made the equipment ready for the next morning. In the morning, the mood was great with the weather being good with high sun and only 6-7 m/s wind, so everything should be ready to dive. But under the high spirits, one could also feel tension we all felt facing such a deep dive on a colossal big wreck without knowing the conditions of the current and the visibility.
Unfortunately, the current over the wreck in the morning was still so strong that the buoys were partly forced down under the water and diving was impossible, but they hoped it would lessen in the afternoon. After lunch, we were then finally told that the current had died down to about 1 knot and all began to load the equipment up onto the diving boat. 11 divers each with a rebreather, scooter, and 3 bailouts and extra tanks for the anchor rope take up quite a lot of space, and you simply must be extremely disciplined to make things work and avoid a shamble of equipment.
The first dive
When we arrived at the buoys over Britannic, there was still some current, but no more than that we figured we would be able to dive. The first team on the wreck had to verify that the anchor was firmly on the wreck and then notify the surface using a marker buoy. The second team consisting of 3 men who dived without a scooter. After an additional 10-15-minute wait, I could finally go into the water with my team consisting of my two Belgian friends Karl and Mattie, whom I have previously dived within Malta and Belgium. Immediately, it became clear that the current was a serious problem as it was at least 1 knot and the anchor line too long. Fortunately, we had relatively powerful scooters with us, so we got down quickly to the wreck.
The team before us without scooters quickly ran into problems, and only one of them reached the wreck. The other two reached only around 20 and 60 m before they had to give up. On the way down, we also met the first team on the way up as well as the last member of the second team who only got about 5 minutes on the wreck. Finally, the wreck appears from around 70 m. It is the port side as well as the port propeller which slowly comes to sight in the twilight around 85-90 m depth.
The wreck seems to be in great condition after 100 years at the bottom. It is splendidly overgrown by corals and algae in green and yellow colors and there is no visible damage to the aft part of the wreck, which is dominated by the huge port propeller with a diameter of just over 7 m and the 2 sets of portside davits protruding more than 10 m from the top deck. The other thing which is immediately noted is the promenade deck which opens up as a recess during a series of openings on the port side and is good to orient yourself by.
After spending some time on the port side to orient themselves on the huge wreck, we went down the side of the wreck and thus down on what once constituted the top deck on the Britannic. Only now is it quite clear that the wreck has been on the bottom of the Aegean for over 100 years because it is really difficult to identify the individual parts of the top deck and time goes to a large extent with the orientation while the deco time accumulates with lightning speed.
The agreement between us was that we had to return to the anchor line when we had reached a time at the surface of about 125-130 min. It’s hard to secede from this amazing wreck, but the idea of over 2 hours of decompression with an unknown current on the anchor line makes us leave the bottom. First, we were not bothered by the current, but on the way up it got steadily stronger, first with relatively mild current ~ 0.5 knots from about 60-70 m rising to up to 2 knots at the deco station at 6 m, where the line quivered under the load.
Fortunately, our team had good scooters with sufficient battery life, so we were able to relieve our arms and the anchor line, which was under a heavy load of up to 9 divers with a water resistance as a medium-sized truck. We were all tired when we were back up on the support boat, but happy to have gotten the first dive well over without any real problems, even if the two which did not reach the wreck were disappointed.
The next 2 days, unfortunately, the weather forecast was poor, but then it looked again sensibly and now we knew the equipment and setup worked satisfactorily. So, the next few days we used to refine the equipment and all the mutual agreements, both within the team and between the different teams. Thus, our team was moved up to the second team because of the problems of the divers without scooters that caused delays and made it more difficult to get everyone in the water with reasonable intervals. In addition, the anchor line should be tightened up by about 40 m so that we could get faster down to the wreck both with and without a scooter.
The second dive
Next dive was 3 days later under almost ideal conditions – wind strength 2-3 and maximum 0.7 m waves as well as high sunshine. We again dived on the stern of the wreck. As a first man on the second team, one must be ready to jump in the water at the same time as the first team for in order to assist in case of problems. On this dive, it turned out that Peter had problems with a sensor on his rebreather and his dive, therefore, ended before it had even started. Instead, I had to change team, in order for Dave to have a dive mate. It was no problem and at the same time, I got the probably best photographer on the trip as a mate.
This time everything went smoothly – almost no current, really good lighting conditions and we knew now how to orient ourselves on the wreck. The pictures from Dave as well as his video clearly show how good the conditions were, with visibility up to about 40 m. Of course, we should also have the signature photo (picture from the plaque) from the portside railing in front of the memorial plaque of Jacques Cousteau as well as pictures of the port propeller.
After the second dive, the weather still held, and we could, therefore, continue the diving on the bow section of the wreck for the 2 following days. It was quite different dives as the bow generally is a lot deeper at around 110 m, so here you almost get down to the sandy bottom. The remainder of the wreck also partially shadows the bow, so it is quite dark and at the same time the visibility sinks to 15-20 m. We also had to orient ourselves of the wreck again now that the anchor line was laid around the fracture in the hull in front of the bridge (picture of the break-in Bow). But even though I’d been nervous about the orientation before the dive, it went pretty well as we had studied the drawings of the ship diligently. This time we would like to look closely at the anchor which is still stuck on the bow and then the bridge section.
The anchor is actually so large (over 10 tons) that I didn’t discover it in the first place when I saw it all a bit from above (picture of the anchor). Later on the bridge, I found one of the double machines telegraphs laying on the starboard side of the bridge. It was initially really hard to identify it, although the Telegraph is one of the things all wreck divers usually look for. Because the wreck is so overgrown by corals and mussels, is on the side and has been exposed to corrosion for over 100 years and individual items are so small compared to the dimensions of the rest of the wreck, you must often look directly at things while having a good imagination to be able to identify the object (picture of the Telegraph). We also tried to enter the engine region via the hole of one of the chimneys.
Unfortunately, it turned out to be impossible because the grid in front of the entrance was still intact and the space too small to pass with all our equipment. It became our longest and deepest dive on the journey with 113-116 m depth, a bottom time of approx. 30 min and a total dive time of over 3.5 hours.
The last dive of the HMHS Britannic
Our fourth and final dive at Britannic was the following day and again at the bow, where we tried to find the entrance to the famous “Grand Staircase” and get more pictures around the bridge. While we got good video sequences from the bridge and promenade covered, we did not manage to find a possible entrance to the “Grand Staircase”. Now I think I probably know where it is, but it is unfortunately too late. The last dive took place early in the morning because the weather now finally looked to change in earnest and make further diving impossible. It was very dark on the wreck, almost like it had been a night, so it was good that we had placed strobe lights on the anchor line. This made it feel a little less sinister to set the heading towards the anchor line in almost complete darkness at 110 m.
Then, the weather completely turned with over 6 Beaufort and nearly 2 m waves and unfortunately announced the end of our expedition. We were just starting to get to know the wreck and could have explored more of it. However, these are the conditions of such expeditions, in which one should initially be lucky enough to be allowed access to the expedition and since being able to implement 4 dives at depths up to 116 m with an average bottom time of over 25 min and total dive time next to 13 hours without any problems is a privilege.
In comparison, there are several of the previous expeditions that have only been able to dive once on the wreck, so you don’t have to complain, though of course you always want more. There are also limits to how much you can bid your body before you either get sick or end up in the pressure chamber. I praise myself happy to have avoided mishaps and been privileged enough to be part of a well-oiled teamwork that such an expedition is. For me, it was by far the most impressive wreck I have dived so far and unlike most wrecks of about the same age, the metal frame is really remarkably intact without in any way starting to collapse under its own weight, as far as I can judge. In addition, most of the tools and the deck planks are still in place, which is absolutely fantastic when you compare with other wrecks around the world.
Paralenz Dive Camera and wreck diving
When you are diving with 3 stage bottles, several computers, powerful lights, and a dive scooter, you do not have a hand free to make videos. This is further pronounced when it is dark, visibility is limited or when exposed to strong currents or even all these things at the same time. Then it is great to rely on the Paralenz to capture the images of unknown environments you see, while you can concentrate on the actual diving. After all, your life is at risk if you make mistakes at over 100 m depth when safe access to the surface is measured in hours instead of minutes.
For me, it is a great tool for the exploration of complex diving environments (e.g. inside a shipwreck, a complex cave or covering large distances by scooter) in the safety of your living room whereby facilitating the decision making for safe execution of future dive-plans without being task loaded. I used the Paralenz on all 4 dives on the HMHS Britannic without any problems and this allowed me and my colleagues to better identify features for closer examination during the following dives and make the decision about where to go next on this gigantic wreck.
At 100 m depth and covering a 270 m long and 28 m wide wreck, you do not have much time to make mistakes and taking wrong turns when every minute on the wreck costs around 7 minutes of decompression. The ease of operation and the clarity of the pictures makes it a pleasure to use the Paralenz and gives you peace of mind while diving.
The diving team for HMHS Britannic
The co-operation on the expedition was nothing short of fantastic, especially to take into consideration that we were a group from 7 different nations in Europe (Belgium, Cyprus, Denmark, the Netherlands, Ireland, UK, and Germany) that basically did not know each other before. Everyone worked hard for each other to be 100% prepared to solve any problems and secure each other as a team.
The whole thing was supported by the dive center at Kea (Kea Divers) who worked around the clock to get all the logistics to operate under the direction of the expedition manager Pim van der Horst who made sure everything went smoothly. It is something you could learn a lot from in your daily work and made it an absolutely unforgettable experience.
Article by Søren Bøwadt
Rebreather diver and IANTD instructor