The Thistlegorm: The Story of a Ship, Its Tragic Fate, and the World's Most Famous Shipwreck

Where : Egypt, Red Sea, 40 kilometers west of Sharm el-Sheikh

My rating : 9/10

Depth : 30 meters

Difficulty : medium

The SS Thistlegorm was a British merchant ship of the Albyn Line, launched in 1940 and over 126 meters long. Built for the transport of cargo, she was immediately requisitioned by the Royal Navy for warfare during the Second World War; immediately after commissioning, the Thistlegorm was equipped with two 4.7-inch anti-aircraft guns.

Her last mission, departing Glasgow on 2 June 1941, was to deliver strategic supplies to British troops in North Africa, passing the Cape of Good Hope and up the Red Sea to Suez.

Aboard the Thistlegorm was a veritable relic of wartime: BSA and Norton motorcycles, Bedford trucks, Lee-Enfield rifles, Bren Gun Carrier light tanks, military boots, spare aircraft wings, even anti-aircraft shells, and two locomotives! After weeks at sea, the vessel anchored in the Sha'ab Ali roadstead, north of Hurghada, along with many other ships, waiting for the port of Suez, access to which was temporarily blocked, to reopen.

But the night between 5 and 6 October 1941 was fatal: a Luftwaffe Heinkel He-111 bomber, heading towards Crete after returning from a mission during which it had failed to find its target, spotted the Thistlegorm at anchor and decided to unload its cargo onto the merchant ship (the largest of the ships at anchor), hitting the ammunition depot at the stern head-on.

The bomber was returning from the opposite direction from which any attacks were expected and the anti-aircraft guns were unable to activate in time when they saw the bomber arriving at low altitude.

The explosion was catastrophic, so much so that it blew the two locomotives that had been loaded onto the deck into the air. The ship sank within minutes, taking with it nine sailors and causing collateral damage to other nearby vessels, such as the SS Sea Star . Fortunately, 32 crew members managed to survive because, due to the unbearable heat on the lower decks, they had moved their bunks outside and were able to jump into the sea upon seeing the bomber approach.

The Forgotten Discovery: Cousteau and The Silent World

For over a decade, the Thistlegorm was "forgotten," at least by the general public (in fact, the wreck's location had already been marked on Admiralty maps since 1948). The Red Sea was not yet a destination for diving tourism, and the wreck was mostly a military curiosity. It was Jacques-Yves Cousteau , the pioneer of modern diving, who rediscovered the site in 1956 during an expedition aboard his laboratory vessel Calypso and popularized it.

In the documentary film The Silent World ( Le Monde du Silence ), winner of the Palme d'Or at Cannes and the Oscar for best documentary, Cousteau narrates the discovery of the Thistlegorm.

At the time, Cousteau also recorded the serial numbers of the vehicles and equipment on board, providing part of the story of the sinking; Cousteau showed a nearly intact wreck, still containing the ship's tableware, compasses, and bell engraved with the ship's name.

Since the 1990s, the site has been rediscovered by Egyptian diving centers and has come to light as one of the most spectacular wrecks in the world and one of the most famous dives in general.

Getting there: logistics and access points

The Thistlegorm lies approximately 40 km west of Sharm el-Sheikh , in the area called Sha'ab Ali, at a depth of 30 to 32 metres . There are two options for reaching it:

1. Liveaboard diving: This is the recommended option for a relaxed dive in the best conditions. Visiting the Thistlegorm on a liveaboard allows you to do up to four dives a day on the wreck, from dawn dives before the arrival of the daily dive boats from Sharm el-Sheikh to night dives after sunset. Four dives are also required to fully explore the wreck. Many operators offer Northern Wrecks and Reefs itineraries that include Abu Nuhas, Ras Mohammed, and the Thistlegorm. These cruises are the best a wreck enthusiast could wish for, encompassing numerous famous wrecks in a single week, such as the Dunraven, the Giannis D, and the Chrisoula K.

2. Day trip: Departure at 4:00 a.m. from Sharm el-Sheikh, approximately three hours of sailing, two consecutive dives on the wreck, and return in the afternoon. This is more strenuous and less suitable for photographers or those seeking in-depth exploration.

Diving conditions: beauty, risk, caution

The wreck lies in a sailing position, well preserved, with numerous possible accesses and penetrations.

As a general rule, the following considerations apply:

• Current: often moderate-strong, especially when rising.

• Visibility: Generally good (20–30 m), but may decrease due to boats above or tides.

• Temperature: 21–29°C depending on the season. In winter, a 5mm wetsuit may be necessary.

• Safety: Maximum depth just over 30 meters → deco limit or nitrox dive. A torch is mandatory for penetrations, and a wreck specialty or intro-to-tech course is also recommended .

The above information is typically found on the websites of dive centers offering dives on the Thistlegorm. Before diving the Thistlegorm, I had also read extensively on social media and diving forums about the dive's characteristics, including numerous alarming reports of divers being dragged far away by strong currents and of dangerous diving conditions due to the numerous boats moving above the wreck.

My experience wasn't that traumatic, on the contrary...

Diving on the Thistlegorm typically involves dragging yourself along the rope that moors the cruise ship to the wreck; this makes descent and ascent quite easy, even in strong currents. In this regard, I'd like to share an anecdote. When I visited the Thistlegorm, the fourth dive of the day was, of course, a night dive. During the briefing, we were informed that the current had increased significantly compared to the day's dives, and we were advised to dive only if we were extremely motivated and confident in our abilities; "As soon as you enter the water, grab the line immediately, or you'll be lost in a few seconds." After this, we decided to dive with only six of the 24 divers on board, while the other 18 cheerfully declined the opportunity. Among the six divers who dived were a British naval officer who was on holiday with his 16-year-old son, who had a total of 15 dives in his logbook; It may be that the English father was a bit reckless in taking his inexperienced son into the water in such predicted conditions, but the dive went perfectly smoothly. At no point did I feel the current was overwhelming, and it was ultimately one of the most beautiful night dives I've ever done. I must conclude that even what local guides consider a very strong current is nothing you can't handle with good buoyancy and a little caution.

The wreck lies on a sandy bottom at a depth of 30 meters in an area exposed to currents. This means visibility isn't always optimal because when the current picks up, sediment also stirs up, significantly reducing sensitivity. However, in the four dives I've done, I'd say visibility has never dropped below 15 meters. Descending along the line, depending on visibility, the wreck isn't immediately visible, but once you reach around 15 meters, its outline begins to emerge, and the view is breathtaking: the Thistlegorm is colossal, imposing, and gigantic. When you reach the wreck, the current becomes less noticeable because the wreck itself offers protection from the current. The current can be noticeable if you move away from the wreck, particularly when approaching the two locomotives that were thrown by the explosion and lie on the sides of the ship. However, as I said, even when the guides warned of the presence of very strong currents, I never found the current to be strong enough to represent a danger.

As mentioned, Nitrox certification is almost mandatory to dive the Thistlegorm; the dive profile consists of a nearly vertical descent and ascent along the anchor line, with the remainder of the dive at a depth of 30 meters inside or to the sides of the wreck. Without Nitrox, it's nearly impossible to complete the dive without undergoing decompression time.

Access to the wreck is not particularly difficult, and it is actually easily navigable with a guide, even for those without a wreck diving certification. The spaces are extremely spacious, and a way out is visible from almost every corner, especially as the wreck is generally very crowded. It would be advisable, however, to be able to perform a frog kick, so as not to stir up sediment and impair visibility for following divers.

The wreck is truly gigantic, over 120 meters long, and at least three dives are needed to fully explore it, from the stern with its imposing propeller and coral-encrusted anti-aircraft gun, to the blast zone riddled with twisted metal, from the caches of unexploded munitions to the holds of trucks and motorcycles. Among the images that have remained most etched in my memory, even after so long, is undoubtedly the sight of the ship's towering walls, observed from below from the base of the seabed. Reaching the bow along the seabed, climbing up the wall to deck level, and seeing the entire wreck appear before my eyes as far as the eye can see is a staggering experience.

The ascent at the end of the dive and the safety stop are always done along the mooring line, where it’s common to have a bit of a crowd of divers all holding on in the tight space between 6 and 4.5 meters. In the four dives I did, I never encountered currents strong enough to risk being swept away if you let go of the line during the safety stop, so in practice it would have been perfectly manageable to hold a neutral position a few meters off the line. However, if you happen to find stronger currents than I did, it can be handy to carry a reef hook to clip into the mooring line during the safety stop — with 12 divers holding on to the line in just a meter of space, you might not find room for yourself.

What to see: an underwater time machine

Diving the Thistlegorm is more than a visit to a shipwreck: it's a journey into a time capsule; the Thistlegorm is a veritable museum of the Second World War, frozen in time and space.

The most iconic parts:

• The main bridge with the tracks, where the two railway tank cars are located.

• The holds : in no. 1 are stacked BSA motorcycles , boxes of rifles, boots, helmets, in no. 2 the Bedford trucks and light tanks.

• The anti-aircraft gun at the stern : covered in soft coral, it is one of the most photographed spots.

• The stern explosion : the destroyed area is a striking reminder of the power of the bombardment.

• The locomotives : they lie on the seabed alongside the wreck and it is on the one hand surreal to contemplate a locomotive on the seabed, on the other astonishing to note the size and weight of the two vehicles and to imagine the power of the explosion that must have had to project them into the air and throw them overboard.

Marine life is abundant: jacks, batfish, turtles, crocodile fish, moray eels, barracudas and the occasional whitetip shark.

Preservation of the wreck of the Thistlegorm

Since the wreck became one of the world's most famous dives in the 1990s, its condition has deteriorated significantly. Not only have all removable parts, starting with the bell immortalized by Cousteau, been removed and looted, leaving only the skeleton of the wreck, now essentially stripped of all its furnishings; carbon dioxide emissions from divers have significantly corroded the metal sheets, prompting the Egyptian government to drill gas escape holes to slow the oxidation of the metals.

Furthermore, the wreck is subjected to mechanical stress because the cruise ships that carry divers to the dive site anchor to the wreck itself.

The wreck is considered a historical monument and is under close observation by the universities (particularly British and Egyptian) that study it and by the Egyptian government; it cannot be ruled out that the Egyptian government will decide to suspend diving on the wreck for a certain period in order to allow the structures to stabilize.

Final considerations and practical advice

• Recommended level: Advanced Open Water or higher, preferably with >30 dives; good trim is required to move around the wreck.

• Typical profile: at least one initial dive to explore the exterior and at least one second for a guided penetration into the holds; in reality, four dives are necessary to calmly explore the entire wreck.

• Equipment: torch, spool, if possible computer with deco planning and nitrox.

• Ethics: The Thistlegorm is a war site and a marine graveyard . Avoid any form of plunder, touching, or disrespectful behavior.

Before visiting the Thistlegorm, I highly recommend reading the book Diving the Thistlegorm , the details of which are provided below. Not only is the book an exceptional tribute to this historic monument, complete with comprehensive information and impressive graphics, including 3D scans of the rooms, but it is also extremely useful during dives for quickly identifying all the artifacts, whose legibility could be compromised by decades of exposure to the underwater environment.

Sources and further information

• Jacques-Yves Cousteau , Le Monde du Silence (film, 1956)

• Simon Brown, Jon Henderson, Alex Mustard, Mike Postons, Diving the Thistlegorm: the ultimate guide to a world war II shipwreck, Oxford, Dived Up Publications, 2020