Text by ADM staff photojournalist Jeff Toorish • Photos by Jeff Toorish and Rick Marshall
“I must confess that my imagination refuses to see any sort of submarine doing anything but suffocating its crew and floundering at sea.” –H.G. Wells
Submarines are, by their very nature and purpose, mysterious. Their mission is to quickly and silently glide to their target, unleash their devastating weapons, and then simply disappear. But the mysteries of U-853 are deeper; deeper even than the 130 feet of cold, dark water that forms her military graveyard off Block Island, Rhode Island.

What we do know is that Unterseeboot 853 is the last German U-boat sunk in a naval battle off the coast of the US.
War Almost Over

At around 5:00 PM on May 5, 1945 the U-853 sealed her own fate when her young commanding officer, Kapitanleutnant Helmut Fromsdorf, ordered her crew to torpedo the S.S. Black Point, a freighter heading to Boston with a load of coal. Fromsdorf was known as a supremely confident commanding officer. He had brazenly operated his boat undetected off the US Northeastern coast since February of that year. A day before U-853’s attack on the Black Point, the German High Command issued a cease hostilities order to all U-boat commanders. Admiral Karl Doenitz of the German Navy had replaced Adolf Hitler as acting Fuhrer after Hitler committed suicide. Adm. Doenitz is quoted as telling Nazi forces, “the struggle against the Western Powers has become senseless.” A deep part of the U-853 mystery is whether Kapitanleutnant Fromsdorf received the order and ignored it, or simply never received it.

Fromsdorf carefully sites his target through a periscope. With deacly accuracy, the torpedo from the U-853 rocketed through the cold Atlantic water and struck the Black Point in the stern section. A 40 foot piece of the Black Point’s stern was blown into the sea. No one of the Black Point saw the torpedo coming, no precautions were taken. The Commanding Officer of the freighter, Charles Prior, and cancelled lookout watches in the tragic belief that hostilities had ended and his ship was in protected waters.
Twelve of the 46 crewmembers aboard the Black Point died in the attack. The ship sank in minutes to a depth of 95 feet; but the victory would prove hollow for the Fromsdorf and his crew. A shallow water attack is extremely risky for a submarine. The U-853 essentially had no place to run after sinking the Black Point. Standard tactics call for the sub to unleash torpedoes, verify the kill and then “go deep,” to avoid detection. That option was fatefully not open to the U-853.

The Kaman, a nearby freighter, registered under the flag of Yugoslavia, radioed the U.S. Coast guard about the attack. Coast Guard and Navy warships quickly assembled and started hunting the submarine visually and with sonar. Eventually they would be joined by two blimps offering air support.

The submarine was in shallow water and had nowhere to go. Fromsdorf tried to hide in nearby shallows but when the USS Moberly and USS Atherton arrived with their compliments of depth charges, a horrific night battle ensued. The Warships relentlessly pounded the submarine. By morning, mortally wounded, the U-853 sank about six miles off the coast of Block Island. Reports at the time cited sailors seeing the white hat of the captain floating on the surface near a large oil slick, the hallmark of sunken submarine. The next day a Navy hard-hat diver descended into the murky waters and confirmed the destruction of the U-853. All hands were lost.
The U-853’s prospects had been different just a couple of weeks earlier when her crew had defended itself against three attacking aircraft, damaging one so badly it was jettisoned after returning to its ship. This is a remarkable feet for a submarine that is the natural prey of aircraft. Kapitanleutnant Fromsdorf had earned the respect of his crew who had nicknamed the U-853 Tightrope Walker.

Rumors Abound

Tightrope Walker has been rumored to be Hitler’s private escape submarine as well as reputed to have carried an immense treasure of silver and gold. The submarine itself was designed to run mostly on the surface. She had significant limitations while submerged.

U-853 employed a schnorkel layout, type IXC, which gives the boat its design. The schnorkel was invented by the Dutch. The German navy co-opted the design after invading Netherlands in May of 1940. Earlier submarines had to run on batteries while submerged, their diesel engines turned off. The older subs spent much of their time on the surface, running their engine to recharge batteries. This created a significant vulnerability.
The schnorkel was a provocative design that allowed the submarine to operate its diesel while remaining at periscope depth. This, in turn, gave the U-853 nearly unlimited underwater range.

But the schnorkel design had significant drawbacks. The boat was limited to about six knots while submerged. Because the diesel was running constantly, the boat was also nearly deaf, increasing its vulnerability. The constantly running diesel engine also presented another problem, with the boat nearly always submerged, the engine had to suck air from inside the hull. While the schnorkel provided plenty of air, the constant suction caused ear problems for the crew.

There were also other problems associated with a boat that runs underwater nearly all the time. For example, the accumulated garbage could not easily be dumped, leading to the obvious safety and health concerns. Crew moral was also problematic for men who often did not see the sun for long periods of time. While U-boat crews were often hand-picked for their loyalty to the Reich, basic human nature also comes into play.

Diving the U-853 Today

New England weather is unpredictable and this dive to the Tightrope Walker has been postponed 5 times because storms. Apparently the sixth time was the charm and on a beautiful spring day in May a team of divers headed out from Point Judith to the U-853. The diving team for this trip included team leader Rick Marshall, Roup Baker, Tony Fiore, Deb Greenhalgh, Jerry Wilkens, Joe Romeiro and Armando Hernandez. Marshall and I would be diving Classic KISS rebreathers, the other divers were diving various single and double configurations. The only mishap of the trip occurred when a small fish called a cunner attached itself to Bakers’s upper lip. The water temperature was a balmy 47 degrees Fahrenheit, and drysuits made for a comfortable dive.

From a technical diving perspective, this is a relatively simple dive. The wreck is in 130 feet of sea water. The trip out to the dive location is about 45 minutes on a fast boat, such as Captain Wayne Gordon’s Canned Air, out of Point Judith. Other technical information on the dive: the boat was sunk on May 6, 1945. It was commissioned on June 25, 1943. Its beam is 252 feet with a displacement of 1,120 gross tons. It sits upright on the bottom with a list to port.

This is a fascinating dive, and particularly appropriate for anyone either in the process of transitioning to technical diving, or trying to gain more experience at technical diving. Diving in this part of the Atlantic is always challenging. Even relatively modest depths, such as 130 feet are tricky and carry more risk because of factors such as cold, darkness and high levels of particulate matter in the water.

The waters of the North Atlantic off the coast of New England are dark and cold most of the year. For this dive, we were blessed with relatively good visibility. It is important to remember, visibility falls into two categories; what you can see in general terms, and effective visibility. About the best visibility anyone can expect in New England is about 30 feet, which we enjoyed on this dive. That means, at 30 feet, we can make out shapes and bright colors, but effectively the visibility is much less for more precise activities.

The U-853 sits upright, leaning slightly to the left. The conning tower is intact and offers a solid perspective of the boat. The boat’s torpedo tubes are visible, as are the mounting brackets for extra diesel fuel. Off the starboard side is a navy anchor and other wreckage but they are normally impossible to see from the wreck of the U-853 itself.

Like many military wrecks, this boat is rich in history and lore. But this boat offers something more than a link to our naval past; it raises questions the answers to which will most likely forever be obscured by the waves of time. If war is Hell, then dying after a war has effectively ended either by mistake or intention must be at one of the lowest circles in Hades. That is the fate the brave sailors of the U-853 who walked the final tightrope on May 6, 1945.

Jeff Toorish is the Chief Photojournalist for Advanced Diver Magazine and ADM E-zine. He lives in North Yarmouth, Maine.

Special thanks to the US Navy War College in Newport, Rhode island.