Located in the heart of the Pacific Ocean, Bikini Atoll is a remote and historically significant destination that offers some of the planet’s best wreck diving. The atoll’s stunning natural beauty and rich underwater history make it a diver’s paradise.
The location was once a U.S. nuclear testing site but is now a popular technical diving destination that attracts shipwreck divers from around the globe. The crystal-clear waters and diverse marine life are a backdrop to famous shipwrecks, from aircraft carriers to submarines and battleships.
Operation Crossroads
The world would never be the same after the U.S. dropped atomic bombs on Hiroshima and Nagasaki, Japan, in August 1945. Soon afterward, the U.S. began planning Operation Crossroads to better understand the effects of atomic weapons on Navy vessels. In this new atomic age, the Navy needed to know if ships could survive a nuclear blast and if surface fleets had become obsolete.
The plan included taking surplus ships to a remote location in the Pacific with a small or no population, preferable weather conditions, and in a territory the U.S. controlled, and Bikini Atoll in the Marshall Islands became the choice. Operation Crossroads ended after two detonations in July 1946, but the U.S. government performed a total of 23 nuclear tests between 1946 and 1958 at various locations in the atoll.
The end of World War II left the Navy with a large surplus of vessels, many obsolete, and their upkeep costs would be high. Surrendered German and Japanese vessels and U.S. ships of all ages and types, from battleships to submarines, were readily available. Britain gave the U.S. the German heavy cruiser Prinz Eugen, once the pride of the Kriegsmarine, which would be used in the tests along with the Japanese flagship IJN Nagato. The USS Saratoga, an 888-foot-long (271-meter) aircraft carrier, and the battleship USS Arkansaswere two of the other capital ships chosen as test targets. The Navy sailed the ships to Bikini Atoll and fully fitted them out before testing so the experiment would simulate fully operational vessels.
The first test, Able, involved a 23-kiloton-yield implosion-type bomb nicknamed Gilda. On July 1, 1946, a B-29 Superfortress bomber dropped the bomb, which exploded about 520 feet (158 m) in the air but missed the USS Nevada, its intended target, by 710 yards (649 m). The damage was less than expected, but five ships of the 95-vessel target fleet sank.
The next test, designated Baker, featured a 23-kiloton underwater detonation. History’s first underwater nuclear explosion occurred at a depth of 90 feet (27 m). Watching the old video of this test is chilling. You see many of the massive ships lined up at anchor. The bomb detonates, and a massive amount of water and sand forms a mushroom cloud high in the air. As the atomic weapon unleashes its power, the large ships look like specks in the water. Despite seeing this historic footage and then seeing the shipwrecks in person, I still find it difficult to describe the bombs’ immense power. The Baker test sank nine ships and left many others badly damaged.
Glenn T. Seaborg, chair of the U.S. Atomic Energy Commission from 1961 to 1971, later called the test “the world’s first nuclear disaster” because of the extensive contamination from radioactive mist and water on the target ships and the atoll. Scientists did not expect such concentrated radioactive fallout from an atomic explosion, and the Navy canceled a third detonation due to this unexpected fallout intensity.
The evacuated residents of Bikini Atoll could not return because extreme contamination had made farming and fishing untenable.
Diving Bikini Atoll
I first heard of Bikini Atoll 24 years ago when a group of technical diving buddies were planning a trip to see these historic wrecks. Diving Bikini is like visiting an underwater museum, and it is some of the best shipwreck diving on the planet. There aren’t many places where you can dive an intact aircraft carrier along with destroyers, battleships, and submarines. These ships are large, some have important histories, and they are all within a short distance of each other, so there is a lot to explore.
Bikini is accessible through Kwajalein Atoll, a U.S. military base that requires prior authorization before you can transit through it. There you promptly board a ferry to Ebeye Island, transfer to a dive boat, and then motor for 26 to 30 hours until you reach Bikini Atoll. The crossing can be rough, so be prepared.
Most of the shipwrecks are close to each other and range from 68 to 187 feet (21 to 57 m) deep. The water temperature is warm, often in the low 80s°F (27°C to 29°C). We experienced currents down to 50 feet (15 m), and a lot of particulate was in the water when I was there, making the water look milky. Conditions vary, but summer months have the best dive conditions and visibility.
Diving Bikini Atoll requires various advanced certifications, including trimix and rebreather. Any wreck penetration requires certification in cave diving or other type of overhead diving. This area is an extremely remote technical diving location, and the closest hyperbaric chamber or medical treatment is between 30 hours and two days away. With that in mind, plan your dive conservatively. Most dives are close to two hours, including decompression obligations. The wrecks are large, so diver propulsion vehicles can be useful. All penetration dives require a guide due to the size and depth of the wrecks.
USS Saratoga (CV-3)
The 888-foot (271-m) aircraft carrier USS Saratoga, launched in 1925, is one of the atoll’s largest and most famous wrecks. It survived the Able test but sank during Baker. Fully loaded with planes, bombs, fuel, and supplies, the carrier sits upright on the bottom. One of the most interesting penetrations is the dive locker area, where you can see Navy Mark V dive helmets and a Morse shallow-water helmet.
Jon R.D. Salas and Mike Dudas discovered this area while exploring the wreck in 2003, as they hoped to get into the sick bay and find the musical instrument room. They had to pry open a hole in the side of the elevator shaft to squeeze inside. All the doors were fully closed, so they worked tirelessly to open them in cramped spaces with no visibility.
“Crammed around the side of the Mark 12 5-inch/.38-caliber munitions elevator was the Mark V box with both helmets in place,” Salas recalled. The lid was askew, so only one helmet was barely visible. He quickly swam several hundred feet back to Dudas, who was deep in reticles and silt, working on opening the door to the dental office.
“I grabbed him,” Salas continued, “and at first he thought there was an emergency because I was so excited and screaming through my regulator to follow me. When he saw the helmets peeking out of the box, his eyes were wide with disbelief. It felt like opening an Egyptian tomb as we lifted the lid to reveal the twin Mark Vs sitting inside.” The pair later opened yet another fully blocked door to find a small dive closet with hoses, two canvas dive suits, and the Morse helmet underneath.
Salas explained that it was truly a combined effort to open the hole off the elevator, the door to a big room over a bomb, and then the door to the room by the bomb elevator where the hidden Mark V box was. The pair eventually found the instrument room, where a beautiful, intact clarinet sat on a shelf next to a stack of sheet music. These dive helmets have become an iconic image of Bikini Atoll. It’s unique to see something like this inside a shipwreck, and they are truly breathtaking.
Another incredible dive is to the sick bay, which was also discovered in 2003, when Dudas was able to open the fastened hatch that went down into the medical space. The sick bay sits at about 135 feet (41 m) at the end of a 500-foot (152-m) multilevel penetration. Divers must navigate through doorways and hallways and down a set of stairs, where there is a scale and the sick bay sign. Several rooms are on the lower level. One contains an operating table, medical tools, and other equipment.
The dentist’s office is also a famous room inside the Saratoga. I’ve never seen anything like it underwater. It’s not very large, but it has four old dentist chairs, sinks, and cabinets with tools still inside. It’s spooky and very easily silted, so there is little time to shoot photos inside. The water often becomes quite turbid, so having to exit on the line is not unusual. Luckily, visibility returns quickly if another team wants to enter during the next dive.
Les Saratoga offers a lot to explore, inside and out, from the hangar to the planes on the seafloor. The command information center is another fascinating area to explore, as are the captain’s quarters and the machine shop. Inside the scullery you’ll see galleys and a cigar lounge with clocks still on the walls. There is even a barbershop. With so much to explore, you could easily spend an entire dive trip on just the Saratoga.
IJN Nagato
Les Nagato is a Japanese battleship that served as the flagship for Admiral Isoroku Yamamoto, who gave the final order for the attack on Pearl Harbor from its pagoda mast. That same pagoda now lies on the seafloor next to the wreck.
This 738-foot (225-m) ship was the first super-dreadnought battleship of the Imperial Japanese Navy. It was modernized between 1934 and 1936, with changes to its hull that brought it to its full length from the original 708 feet (216 m) and to its steam turbines, defenses, and armament. That is also when the pagoda mast was added, with platforms, lookouts, and shelters that made it resemble a temple pagoda.
Les Nagato was placed at a relatively close distance of 2,854 feet (870 m) from the underwater explosion during the Baker test, allegedly because the Navy wanted to ensure the Japanese ship would not stay afloat when American ships sank. The ship had very little apparent damage after the blast and sank about five days later when it capsized and rolled beneath the waves.
The wreck lies upside down at about 170 feet (52 m). The wreck quickly comes into view as you descend because it stands high off the bottom. The four massive propellers and the stern rudder lie at about 108 feet (33 m). The 16-inch stern guns are just below, still in the turret. They measure about 50 feet (15 m) long and are one of the wreck’s most impressive sights.
You can easily do several dives on the Nagato, both inside and outside, seeing the remnants of its grand structure and the diverse marine ecosystem surrounding the site. It’s a significant dive site for those interested in World War II history.
USS Apogon (SS-308)
The Navy had 120 Balea-class submarines built during and after World War II, including the USS Apogon, which was 311 feet, 6 inches (95 m) long, and launched in 1943. This submarine class could operate below 400 feet (123 m) and carried more fuel for longer missions. Like others during World War II, these submarines had torpedo data computers, which allowed for the tactically advantageous launch of torpedoes on a course different from the submarine’s.
Les Apogon was moored at a depth of 100 feet during the Baker test. The underwater explosion’s pressure wave proved devastating and promptly sank it. The submarine is intact on the seafloor and upright in about 165 feet (50 m) of water. The conning tower is still upright and appears to have deformed from the pressure wave that burst open the submarine’s watertight seals and filled it with water.
Glassfish surround the Apogon, and coral encases the deck guns. The submarine itself is an interesting dive, but the marine life makes it even more spectacular. Torpedoes are still visible inside, along with shells on the deck, deck guns, and the picturesque propellers. Divers can swim beneath the stern for a unique view, looking out at the props and rudder.
USS Lamson (DD-367)
The USS Lamson (the third Navy ship with that name) was a Mahan-class destroyer that launched on June 17, 1936. During World War II, the Lamson served in the Pacific Theater, participating in several critical naval operations and engagements, from operations at Guadalcanal to screening duties at Iwo Jima. The ship survived a kamikaze hit in the Philippines and played a significant role in anti-submarine warfare and convoy escort missions. It sank as part of the Able test.
The destroyer has a picturesque bow and is covered in colorful coral and marine life. There is still a good amount of structure, several antiaircraft guns, torpedoes inside deck-launch tubes, and depth charges on stern racks.
USS Arkansas (BB-33)
Launched in 1911, the battleship USS Arkansas served in both World Wars and earned four battle stars. The Wyoming-class ship escorted convoys to Europe through 1944 and supported the invasion of Normandy. The ship moved to the Pacific in 1945 to take part in bombardment during the invasions of Iwo Jima and Okinawa. After the war it participated in Operation Magic Carpet, ferrying troops back to the United States.
Les Arkansas sank during the Baker test. Some say the black shadow in a historical photo of the mushroom cloud is the Arkansas being lifted vertically by the blast. The wreck lies at a depth of approximately 170 feet (52 m) and is known for its impressive structure, featuring its gun turrets and many accessible compartments.
Parting Thought
It’s important to keep history alive and not forget the stories behind these ships and the Bikini nuclear tests. Why dive a place where nuclear weapons were tested? Seeing the wide variety of shipwrecks that make up the Bikini nuclear ghost fleet brings into perspective how incredibly powerful and destructive one relatively small nuclear bomb is.
These ships and their histories make Bikini Atoll one of the most interesting shipwreck destinations, despite the ships being sunk on purpose. To be able to dive a Japanese battleship and an American aircraft carrier, submarine, or destroyer on the same day makes this a unique place. The area has many other incredible wrecks to dive, including the Prinz Eugen in Kwajalein Atoll on the way to Bikini or the USS Pilotfish, USS Anderson, and USS Carlisle in Bikini Atoll. The ships are now covered in coral and marine life, making them large artificial reefs that attract a lot of biodiversity, including sharks and turtles.
Unfortunately, the testing caused a lot of damage to the environment. The atoll still has no residents, and the only regular visitors are tourists, scientists, and caretakers who live nearby. The soil still contains significant levels of Cesium-137, meaning that visitors cannot eat any produce grown on the island.
Many of the shipwrecks are leaking oil, which looks like a shiny river on the water’s surface. Projects are underway to explore the problem further, as these ships have been underwater for nearly 80 years and continue to deteriorate. In 2018 a Navy salvage team removed 229,000 gallons of oil from the Prinz Eugen. Despite these issues, Bikini Atoll remains at the top of most technical divers’ bucket lists, and underwater photographers will enjoy the clear blue water with intact shipwrecks and colorful marine life. It’s a place to dive into World War II history, where each shipwreck tells a unique story and offers a lot to explore.
En savoir plus
See more of Becky Kagan Schott’s dives at Bikini Atoll as well as historical footage of Operation Crossroads in these videos.
© Alert Diver – Q1 2025