HMHS Britannic (Kea Island, Greece — 385 fsw)


The HMHS Britannic is, according to many, the pinnacle of wreck diving. I have always dreamt of diving the wreck but it was always “out of reach” for many different reasons. Until now.

Some people have compared diving the Britannic to climbing the infamous Mt Everest. I would liken it more to scaling the slightly lower, but technically much harder, K2 which is known as the “Savage Mountain” after the famous climber George Bell said to reporters about K2 that “It’s a savage mountain that tries to kill you.” As of Feb 2021, there have only been 377 people who have ever summited K2 and 91 deaths during attempted climbs. Savage Mountain indeed.

I’m almost positive there have been way fewer than 377 people that have ever dove the Britannic….

We were a team of four divers (Ben Lair, Justin Judd, and me) and a local dive guide (George Vandaros) and we successfully dove the Britannic four times during our recent visit. I will provide background on the HMHS Britannic, how she sank, details of the equipment we used, and a summary of each dive along with some amazing pictures (if I say so myself)!

We did all our diving with Yannis @ Keadivers and his excellent staff. I covered a lot of the details of Keadivers in my initial Trip Report for Kea, Greece. It is really important on deep, open ocean dives like this that you use a dive operator that knows what they are doing and has done this type of diving many times. I can’t say enough about the quality, safety and thoughtfulness of the Keadivers team.

Below are hot links to descriptions of the four dives in case readers want to skip the history and dive equipment sections and just look at the pretty pictures.

  • Dive 1 : Orient on the wreck and explore the bow section, explosion area, and bridge
  • Dive 2 : Stern & props
  • Dive 3 : Stern & props “re-do”
  • Dive4 : Promenade deck swim through

HMHS Britannic

The Britannic was the third ship of the Olympic class of steamships. The first was the eponymous Olympic, the second was the iconic Titanic, and the third was the Britannic. The Britannic‘s keel was laid on 30 Nov 1911 at the Harland and Wolff shipyard in Belfast. After the Titanic disaster, they made some improvements to the Britannic and she was launched on 26 Feb 1914 and they started fitting her out.

Some of the improvements in the Britannic included more and better lifeboat davits, the introduction of a double hull along the engine and boiler rooms, and changes in the watertight bulkheads. As we will see, none of those improvements prevented her from sinking in a record 55 minutes — much faster than the Titanic

In August 1914, World War I broke out and the fate of the Britannic was to be changed forever. On 13 Nov 1915, the Admiralty requisitioned the Britannic to be used s a hospital ship. She was repainted in white with large red cross logos and a horizontal green strip and renamed to His Majesty’s Hospital Ship (HMHS) Britannic.

Drawing from

Note the big crane-like lifeboat davits on the ship. This was done after the Titanic sank. Each davit was capable of holding six lifeboats. She carried 48 lifeboats capable of carrying at least 75 people each for a total of 3,600 people which exceeded the max number of people the ship could hold.

She was never used as a luxury liner and spent her entire career serving the Admiralty. Therefore, she doesn’t have many of the luxury fittings that were on the Olympic and the Titanic.

Some quick stats on the Britannic:

  • Laid down : 30 Nov 1911
  • Completed : 12 November 1915
  • Length : 882 ft 9 in (269.1m)
  • Beam : 94 ft (28.7m)
  • Height : 175 ft (53m) from the keel to the top of the stacks
  • Speed : 21 knots (24 knots maximum)
  • Capacity : 3,309

It is hard to describe her size when you first encounter her underwater. She is nearly three football fields in length.

During the conversion to a hospital ship, the common areas of the upper decks were changed into rooms for the wounded. The cabins of the B deck were for doctors and the first-class dining and reception on the D deck were converted into operating rooms.

Her first service was in December 1915 and involved transiting from Liverpool to Moudros on Lemnos Island in the Aegean Sea. She was to pick up wounded and sick soldiers and bring them back (similar to her final voyage in the map below). She made two additional voyages in service to the Admiralty.

After this initial service period of three voyages, she was returned to Belfast in June 1916 to be retrofitted for the original purpose of luxury transatlantic passenger service. The British government paid them 75,000 GBP for the conversion. Midway through the conversion, in August 1916, she was recalled back into military service. She returned to the Mediterranean for a fourth voyage in September 1916. Her fifth voyage was back to Moudros.


The Britannic was on her 6th voyage after 5 successful missions and was steaming towards the British Naval Base at Moudros on the Island of Lemnos. She rounded Cape Matapan in the early morning hours of 21 November and steamed towards the Kea channel en route to Lemnos. There were 1,066 people on-board including 673 crew, 315 Royal Army Medical Corps, 77 nurses, and the captain.

At 8:12am, she was rocked by a large explosion near the bow of the vessel.

At the time, they didn’t know what caused the explosion (torpedo or mine) but the reaction was instantaneous. Both Captain Bartlett and Chief Officer Hume were on the bridge and they knew that they were in trouble. The explosion had damaged one of the forward bulkheads and the first four watertight compartments were filling with water. The fireman’s tunnel connecting the fireman’s quarters and the boiler room was also damaged resulting in water flowing into the boiler room. (NB: A “fireman” on a ship isn’t a “fire fighter.” It is somebody who keeps the fire going to ensure running of a boiler or powering a steam engine.)

The Captain ordered the watertight doors closed and sent out a distress signal while ordering the crew to prep the lifeboats. The watertight door between boiler room five and six also failed to close resulting in water flowing into boiler room five in addition to six.

She was at her flooding limit.

BRITANNIC’s flooding limit. Green:Firemens tunnel/Purple: Watertight bulkheads (digital elaboration by Michail Michailakis).

In theory, she should have been able to float at this point. The bulkhead door between boiler room five and four should hold. However, there was a problem: open portholes along the lower deck which was tilted underwater within minutes. The theory is that nurses had opened the portholes to ventilate the wards. She continued to list and then water began to enter the aft areas through the portholes and she had more than six compartments flooded.

Disaster loomed.

Literally within two minutes of the explosion, boiler rooms five and six had to be evacuated. Within ten minutes, the Britannic was in similar shape to the Titanic after an hour. The Captain made a desperate attempt to get to Kea Island which was only about 3 miles away. His rudder was not working so he had to use propeller power to steer the ship.

At this point, the stewards were preparing the lifeboats and there was chaos, fear, and panic. Two lifeboats were nearly lowered into the water but they noticed the props still spinning so they halted them. The people in the lifeboats were livid because they didn’t realize the reason for the halt.

The Captain ordered that no lifeboats be lowered as he was attempting to beach the massive Britannic. In all of the chaos, two boats were lowered and dropped from 6 feet and slammed into the water. They soon drifted back to the massive propellers which were partially out of the water as the Britannic was sinking bow first. The lifeboats were torn to pieces along with all 30 passengers.

One thing to keep in mind is that the Britannic is over twice as long as the depth of the water where she sank. The HMHS Britannic Weebly website has some cool drawings that show the likely progression of the sinking Britannic. Note how the propellers are out of the water in this sequence.

At this point, the Captain gave the order to stop the engines moments before a third lifeboat was about the be shredded. He gave the order to abandon ship at 8:35am. By 8:45am, the list was so bad that davits on the starboard side weren’t able to be operated. At 9:00am, there was one last blast from the sip’s whistle and Captain Bartlett was swept overboard from the bridge (he survived). In total, 1,036 people were saved and 30 people lost their lives due to the prop accidents.

By 9:07 the Britannic was sunk — just 55 minutes after the explosion.

NY Times Nov 23, 1916

The Wreck

The Britannic, even given it’s large size, went undiscovered until 1975 when none other then Jacques Cousteau found and identified it.

This was quite a feat that is detailed in the Kohler & Hudson book. Keep in mind that in 1975, Trimix gasses were highly experimental but it was unrealistic and suicidal to dive the Britannic on regular air. They had the interesting three tank setup but they still had the problem of dealing with a massive decompression obligation to deal with and drysuits had not been invented. Instead, they had a portable decompression chamber which they would lower into the water and the divers would enter around 200 feet deep. The chamber would then be lifted onto the Calypso and they would serve their decompression obligation out of the water. They made 68 dives on the wreck with about 10-15 minutes bottom time on each dive and an estimated 10 hours of total bottom time.

One of the big mysteries that loomed was whether the ship sank due to an underwater land mine or from a torpedo from a German U Boat. If it was the latter, it would be considered a serious war crime since the Britannic was clearly marked as a hospital ship. Cousteau had expressed that he felt it was from a torpedo. A number of dive expeditions over the years have conclusively proven that it was from an underwater land mine.

The wreck itself lies on her starboard side and is nearly completely intact which is amazing since it has been underwater for 107 years. One theory is that the orientation of the wreck helps maintain it. The current generally flows across the keel which shelters the deck of the wreck. Near the bow, you can clearly see the massive rift in the ship where the mine exploded.

Dive Details

For anybody who wishes to dive the Britannic, I have put together some notes that will hopefully be helpful. I covered some of this in the trip report but will provide more details below.

Side note: any time dives at this depth are conducted, there are a variety of thoughts on how much gas to bring for bailout, whether to use team bailout concepts, whether to stage bailout tanks on the downline, which gasses to bring, whether Isobaric counter diffusion (ICD) is a factor, whether HPNS is a factor, etc.

I will detail what we did as a team. I have done a lot of diving with Ben Lair and Justin Judd and one of the reasons we did this trip together is that we tend to agree on the approach to the risks and factors listed above. Readers are free to disagree with any of our decisions and make your own decisions when doing this type of diving.

Rebreathers and Bailout

First, we had three different types of rebreathers on the dive. Our guide George Vandaros was using an AP Diving Inspiration, Ben & Justin were both diving Dive Rite Chest Mount O2ptimas or “Choptimas”, and I was diving a rEvo. The Choptima has an interesting form factor and does not include on-board diluent tanks; instead, the unit’s diluent is sourced from a bailout cylinder. As far as we know, this is the first time that the Choptima has been used to dive the Britannic.

My equipment list consisted of the following:

  • rEvo rebreather with steel 3l tanks ‘on-board’ and a drysuit inflation tank
    • Diluent was generally about 7/70 (7% oxygen, 70% helium)
  • Deep bailout of 10/72
  • Intermediate bailout of 20/36
  • Oxygen bailout
  • Scooter (supplied by Keadivers)
  • Sony a7rIV camera in a Nauticam housing with Retra flashes (and sometimes Keldan video lights)

Because of the way the Choptima is configured, Ben & Justin had an interesting setup. Keeping in mind that a typical bailout on a dives like this will generally require a lot of “intermediate” bailout gas, they had back mounted doubles with something close to 21/35. Each Choptima diver carried the following:

  • Chest Mount O2ptima
  • Deep Bailout & Diluent (10/70-ish)
  • Back mounted Doubles with 21/35-ish
  • One diver carried Nitrox 50 and the other carried O2
  • Each had a scooter
  • Ben had a camera for video and Justin had a ton of video lights

Our guide carried four AL80 bailout cylinders. I don’t know exactly which gasses he carried, but I’m assuming it was something close to 10/70, 21/35, 50% and O2.

In addition, we had the Keadivers safety team “pre-stage” a tank of Nitrox 50 at 70 feet deep and a tank of O2 at 20 feet deep.

We were using team bailout diving principles which assumes that the team stays together and that not all of the rebreathers fail catastrophically on the same dive and/or you can get back to the upline that has the staged tanks (amongst other assumptions).

One side note: when problems happen underwater, they are often complex (compared to complicated) and need to be fixed immediately and without going to the surface to sort them out. Complex problems change based how we go about solving them and are very dynamic, hard to control and to predict. Complicated problems are generally not easy to solve; however, they have a solution that can generally be knowable and solved. It is also true that a complex problem can quickly become a chaotic problem whose results are often catastrophic.

Dive Planning

For each dive, we would discuss our plan for the dive and our objectives. We would also discuss contingency planning and go through multiple failure scenarios to ensure everybody was in sync. This is absolutely critical for successful dives. One lesson we learned is that, at this depth, simple plans are much better than complex plans. We had a lot of photo and exploration goals but when you try to put too much into a single dive, it generally doesn’t work well.

As Mike Tyson famously said, “everybody has a plan until they get punched in the mouth.” Sometimes when you are doing really deep, complex dives like this, you get punched in the mouth and you have to adapt your plan.

Needless to say: this is very much team diving where the team comes up with objectives and helps each other achieve them.


Below is a video that shows what it is like to splash and then head down to the wreck. It is an amalgamation of two different videos shot by Justin Judd that I put together and sped up 8x. It is hard to describe just how long it takes to get down nearly 400 feet even with a scooter.

The long descent (video from Justin Judd)


We are often asked “how do you stand that much boredom on decompression?” We have an answer for that: DiveVolk with an iPhone. Except for the day when there was massive current, we would have the safety diver clip on our DiveVolk housings to the tank at 70 feet so that we could watch TV, movies, or listen to music during most of our deco!


A final note on photography: Underwater photography is hard enough with the lack of light and color and the need to monitor your breathing apparatus while taking pictures and making real-time camera and lighting setting adjustments. Underwater photography at nearly 400 feet poses immense challenges — especially wide angle shots which large wrecks really “need.” There is just not much ambient light at that depth and you cannot illuminate an entire wide angle scene with “on-board” lighting. My approach on most pictures was to really crank up my ISO (8000+) and rely on lighting carried by the other divers for color.

In general, the plan worked well. My best shots are NOT the ones I had illuminated by flash. There is definitely a “unique” ambience to the photos and I haven’t seen a ton of it on the Britannic. Rick Ayrton’s book and notes were very helpful in pre-trip preparation.

My photography equipment consisted of the following (note: I’m not sponsored by or receive any discounts on any of this equipment):

  • Sony a7rIV camera
  • Sony 28mm F2.0 lens
  • Nauticam a7-rIV housing (outfitted with springs for 120m)
  • Nauticam WWL-1B wide angle wet lens
  • Keldan 8x 18k video lights (carried by other divers “off-board”)
  • Retra Strobes (only rated to 100m but did fine)

On old wrecks, sometimes a black and white treatment really works well so I’ve presented some of the photos converted to B&W.

Dive 1 : Bow Section

Our plan for dive one was to spend some time at the large crack in the hull near the bow, then move out towards the bow to look around, then for Ben & Justin to light up the bridge area and take some photos. The plan worked well and I got some really cool photos of all the divers on the wreck which indicates some sense of the scale.

Below is a selection of photos from the first dive. Most of these were with natural light and shot at very high ISO.

Divers at the “crack” in the hull near the bow. From top to bottom are George, Ben, and Justin. (1/60th, f/8, ISO 8000)

If you click on the photos , you will get a larger version.

Dive 2 : Props

Our plan was to spend most of our time at the props taking pictures and video. I was going to evaluate the possibility of starting a photogrammetry model of this area. George had mentioned that sometimes you can’t see the props from the downline. In that case, he would tie off and find them and come get us. However, on the way down, Ben & Justin were ahead of George and I and we could clearly see the props so we just immediately went there.

The props are a very interesting design. There are matching three-blade props on the port & starboard side with a four bladed prop in the middle in front of the rudder.

I got in position to take pictures and…my shutter wouldn’t work. It was very odd. The camera would focus, but when I triggered the shutter, it wouldn’t activate. Then a few seconds later it would work after I pressed a few other buttons. I did the standard turn off and turn on the camera to no avail. I had a GoPro running, but was very disappointed after all the prep work for the dive. I let Ben, Justin, and George know that my camera was on the frtiz so they wouldn’t wait for me to take photos.

I continued to shoot and the shutter would activate occasionally but it was very unpredictable. You just don’t have a lot of time to figure out camera problems and need to prioritize dive safety and execution. In spite of the camera oddities, I did manage to get some good photos!

The first photo below turned out to be a very interesting coincidence. If you look closely, you can see all three props in this picture. Rick Ayrton had done a similar shot in his book; however, it was from below. Ben is lighting the “top” prop, with Justin under the wreck checking out the starboard prop, and George is near the center prop. If George was just slightly closer to the center prop, it would have been perfect!

Three props on the Britannic (1/60th, f/10, ISO 8000)

After I got back, before I took the camera out of the housing, I tried to troubleshoot the problem while I had plenty of time and air to breathe. It turns out that the camera got into a “drive mode” where there was a shutter delay and then it would take three photos within some kind of bracketing with different exposures. I still don’t know how it got into that mode.

Dive 3 : Stern ReDo

We had a couple days off due to wind and swells but we were back at it. Given the camera issues I had on the previous dive, I really wanted to get another chance on the photos with all three props “properly” illuminated. We also wanted to get pictures of a diver coming up between the middle prop and rudder, and then also portraits of Ben & Justin at the port prop. This is where planing to do “too much” on a single dive can really be an impediment to doing anything … and also a lesson in how things can go awry

Our plan was for Ben & Justin to splash first, then get George and I into the water to meet up with them. By the floats on the downline, we could tell that there was a pretty strong surface current running. Ben & Justin got in just fine and got to the line. When George and I splashed, we either waited too long to get on the scooter trigger, got disoriented, or weren’t dropped far enough up-current. Even with George’s powerful scooter on high, we could not get to the downline.

We literally had to do a complete reset which means taking off ALL of our equipment, getting back on the RIB, putting all of our equipment back on, then getting back into position and splashing. Meanwhile, Ben & Just had no idea what was going on and had descended to about 90 feet to get out of the current and started racking up deco obligation before the dive really even got started. They had almost 10 minutes of deco when we got to them.

By this time, they were pretty pissed and didn’t know about the surface challenges. I caught up with them at the wreck and Ben was taking video of the stern deck areas and I saw Justin disappear over the portside rail towards the props. Ben continued to take videos so I figured that, due to current, we would abandon the plan and stay on the sheltered side of the wreck. After a couple minutes, I heard Ben yell at me “well, are we going to do this or not?”

Needless to say, the dive was a bit of a challenge and we didn’t achieve our objectives but we had a good dive. Deco was not fun as the current above 70 feet or so was raging. Here is a short video Justin took of the safety diver coming down to check on me. Note how fast the bubbles from his regulator disappear! I was having some unexplained buoyancy issues as well and you can see how taught the Jon line is that I’m holding onto.

Me on deco in heavy current (video by Justin Judd)

Below are some pictures from the dive. At least my camera was working on this dive even if our grand plan went to crap!

Setting up for the photo. (1/40th, f/8, ISO 10,000)
Ben is at the port (top) prop, George is at the middle prop. Justin is underneath. This gives a sense of scale and the cool curvature of the rudder/keel.

Dive 4 : Promenade Deck Swim-through

George had mentioned to us at one point that you could swim through the entire promenade deck corridor from near the stern to the bridge area near the bow. Given the complexities of the previous dive, we decided on a simpler plan for dive 4:

  • George & I would enter the water first, followed by Ben & Justin.
  • We would meet on the line and descend together
  • George would show them the entrance to the promenade and then I would follow with George atop them and take photos.
  • George and I were also going to look for the famous Cousteau plaque which is somewhere along that route
  • Near the end of the route, I would zoom ahead and take photos of Ben & Justin exiting the promenade at the bridge
  • Reverse course and head up the line (again looking for the plaque)

Believe it or not, that is a “simple” plan compared to Dive 3. The dive went great and all went according to plan — except, we didn’t find the plaque. 🙁

However, I got some really cool photos of them inside the corridor. We had a decent current at the shallower deco stops. Not quite as bad as the previous day, but still justified using a Jon line. It was interesting because the deco stops between about 100 feet and 50 feet were almost no current.

Below are photos from the dive. Keep in mind that the ship lies on her starboard side so this is going through the promenade deck corridor on the port side and the “top” that I’m shooting photos through of the divers below me would actually be the windows that looked out to the ocean (it is rotated 90 degrees clockwise).

Diver inside the promenade deck corridor with George on port side

Ben was recording video of their traverse through promenade deck. I’ve posted his video below. Remember that “up” is “left” since the ship lays on her starboard side (i.e., the “ceiling” is on the right and the “floor” is on the left”).

Video of the promenade deck traverse by Ben Lair

Summary & Future Plans

Diving the Britannic fulfilled a very big dream of mine and checked a box on the list — for sure. It is an absolutely epic dive that is very hard to describe in words and pictures. I’ve done my best with this post. It really is what I would consider the pinnacle of wreck diving.

It isn’t easy to dive the Britannic and it requires a lot of training and diving to be ready for it and to successfully execute a dive. Given the changes in the permit laws, one major hurdle has been lowered.

If you want to dive this amazing wreck and make it even easier by offloading a lot of the logistics and planning and go with someone who has “been there, done that,” then I would recommend joining one of the expeditions already planned and scheduled by Ben Lair and Paragon Dive Group. Full details and information are at:

Travel – HMHS Britannic Expedition – September 16-29, 2024 (Also 2025-2027 Dates)

I have a list of projects that are left unfinished. I’m not sure I will get back there, but if I do…

  • Start a photogrammetry model of the stern (I think this would realistically require a scooter mounted camera)
  • The “one perfect propeller shot” that includes all three props illuminated from above
  • Find and photograph the Cousteau plaque
  • Photographs of the first class stairwell
  • Participate in an expedition with an internal penetration permit
  • I’m sure there are many others…


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