Diving Into My Family’s WWII History

by Robert Leenen, with Cor Kuyvenhoven and Anton van Rosmalen. Photos by Cor Kuyvenhoven unless noted.

As an enthusiastic technical diver, I have had the privilege of exploring many shipwrecks worldwide. The backstories of these wrecks have always fascinated me. From the Salem Express in Egypt, which tragically sank after hitting a reef (incidentally, my first wreck dive in 1998), to the Loredan, a cargo ship torpedoed during World War II in 75 meters of water off the coast of Sardinia, each wreck tells a story of drama, tragedy, and history. The wrecks and the objects within them are like snapshots of the past, frozen in time. Yet, they also hold human stories—who were the crew or passengers? What exactly happened to them?

My Connection to the Tirpitz

Over the years, I have always kept one particular shipwreck in the back of my mind—a wreck that holds a special connection to my family: the German battleship Tirpitz. As the sister ship of the famous Bismarck and weighing 42,000 tons, it was the largest battleship ever built in Europe. My grandfather, Jan Gijsbert “Bert” Boon von Ochssée, shared stories about this ship from his youth. In 1944, as a 23-year-old fighter pilot, he participated in attacks on the Tirpitz during World War II.

After escaping the Japanese occupation of Indonesia, my grandfather fled to Australia. Already holding a private pilot’s license, he received military flight training in the USA before being sent to the UK for further training on the F6F Hellcat. Alongside several other Dutch pilots, he was assigned to the 1840 Naval Air Squadron of the Fleet Air Arm, operating from aircraft carriers. In July and August 1944, during Operations Mascot and Goodwood, his squadron conducted a series of attacks on the Tirpitz.

During these missions, my grandfather and his wingman, Lt. Cdr. Ron Richardson, dropped bombs on the Tirpitz, destroyed several Flak ships, as well as two Arado Ar 196 floatplanes and a radar station. However, tragedy struck on August 24, when Ron’s Hellcat was hit while pulling up after releasing his bombs on the battleship. His plane disappeared into the Tirpitz’s smokescreen. 

My grandfather’s Hellcat was also badly damaged, and he barely managed to return to the carrier alive. The memory of this particular mission and losing his squadron commander, wingman, and friend was one he never spoke of without tears.

Despite the damage inflicted, the Tirpitz was not destroyed during these missions. It took several more attacks before the battleship was sunk on November 12, 1944, near Tromsø, Norway.

Planning the Trip to Norway

In 2024, marking the 80th anniversary of Operations Tungsten and Goodwood, I decided it was time to visit Norway and dive on what remains of the Tirpitz. Joining me on this journey were my good friends, Cor Kuyvenhoven and Anton van Rosmalen.

As part of our preparation, we revisited my grandfather’s meticulously kept flight logs and wartime diary. The diary, filled with photos, maps, and drawings, was meant to be sent to his parents in the event of his death. Among these records, I also found a recorded interview where my grandfather recounted his wartime experiences, particularly his involvement in the Tirpitz attacks. This set the emotional stage for our trip.

Just days before our departure, I stumbled upon an article mentioning the recent discovery of a crashed F6F Hellcat near the fjord where the Tirpitz had been attacked. The aircraft was confirmed to belong to Ron Richardson, my grandfather’s wingman. The article mentioned Philip Richardson, Ron’s grandson, whom I managed to contact. Our phone conversations about our shared family histories were enlightening. Philip shared the coordinates of the crash site and the location of Ron’s original grave, prompting us to adjust our plans to visit these significant sites.

The Dive

Upon arriving in Norway, we began our exploration by diving at the Tirpitz’s final resting place near Håkøya island, just outside Tromsø. Damaged during earlier operations and in an attempt to evade the proceeding Russians, the Tirpitz had been relocated from Alta to Håkøya. This, however, placed it within range of British Lancaster bombers that eventually sank the battleship in November 1944 during Operation Catechism, using 12,000-pound Tallboy earthquake bombs—the heaviest bombs of their time.

The weather on the dive day was perfect. After collecting our tanks from Tromsø Divecenter, we headed to Håkøya. A small memorial adorned with fresh flowers marked the site, alongside several Tallboy craters and remnants of dismantling efforts from the 1950s. No boat is required to reach the dive site; it’s an easy shore dive. …that is, if you manage to wrestle your way past the many electric fences that surround the cattle fields on shore. 

Though most of the 250-meter/820 feet long wreck was scrapped for its valuable steel, a large debris field remains. Swimming parallel to the shore, we explored a haunting underwater scene: escape hatches, pieces of machinery, teak deck wood, electrical wiring, and rusted 150mm shells. Personal artifacts, including countless shoes, serve as somber reminders of the more than 1,000 German sailors who perished here. 

Floating amidst the wreckage of the ship my grandfather once targeted, I was struck by a profound sense of awe and respect. Though the dive reached a depth of only six meters—my shallowest wreck dive ever—it was by far the most meaningful.

Grandpa’s Wingman

Later that evening, we spoke with Philip Richardson and his father Alistair via video call. Alistair, born just six weeks before his father’s death, shared their family’s reflections on Ron’s legacy. Their insights added depth to our understanding of this shared history.

The following day, we drove to Alta to visit the crash site of Lt. Cdr. Richardson’s Hellcat. The site is scattered across a cliffside, with pieces of the aircraft—wings, fuselage, and the Pratt & Whitney ‘Double Wasp’ R-2800 engine—spread across the area, bearing the scars of intense ‘flak’ anti-aircraft fire. The pattern of the crash site paints a picture of Ron trying to pull up through the smokescreen in his severely damaged plane but sadly clipping the top of the cliffs, resulting in the crash that ended his life. 

On behalf of my grandfather, we laid flowers at the original grave site of his crashed wingman. A very special moment.

A Meeting, 80 Years in the Making

Philip Richardson is also a military pilot and—like his grandfather—a squadron commander in the Royal Navy. Two weeks after our trip, Philip invited me to a memorial service for the Royal Naval Volunteer Reserve (Air) Branch pilots, held at Yeovilton Naval Air Station. In 1944, both our grandfathers trained at this airfield, flying the F6F Hellcat. Meeting Philip in person and visiting this historic site was an unforgettable experience, made even more special by conversations with Fleet Air Arm veterans.

When we booked our plane tickets for Norway, we never anticipated the profound journey that lay ahead. What began as a dive on the Tirpitz wreck evolved into a deeply personal exploration of history, loss, and legacy, capped by meeting the Richardson family and honoring our grandfathers’ shared sacrifices.

Jan Gijsbert “Bert” Boon von Ochssée 
After operations in Norway, Bert and his squadron saw action in the Philippines and supported the American invasion of the Japanese island of Okinawa. His ship, HMS Indomitable, survived several Kamikaze attacks. After the war, Bert joined the Royal Netherlands Navy and flew the PBY Catalina, Fairey Firefly, and Mitchell B-25. He passed away in October 1999, a few months after his war diary was published in Dutch as ‘Van Tirpitz tot Kamikazes’.

Robert Leenen
Robert is an IT project manager who began scuba diving in 1997. In the early 2000s, he alternated between his university studies and working as a dive guide in Thailand. After earning GUE Tech and Cave certifications, he joined the European Karst Plain Project (EKPP) as a support diver. In the years that followed, Robert participated in cave exploration projects that include Doux de Coly, Gourneyras, and Pozo Azul. He was also one of the driving forces behind the DIR Netherlands (DIR-NL) dive group.

Cor Kuyvenhoven
Cor is a dedicated underwater photographer and passionate wreck diver, renowned for capturing the hidden beauty of marine life. He also contributes his expertise to the Ghost Diving Foundation, documenting their efforts to remove ghost nets and restore underwater habitats. Through his photography, Cor aims to inspire greater respect for the oceans and promote marine conservation. Cor’s photo portfolio is available at www.corkuyvenhoven.nl.

Anton van Rosmalen
Although Anton van Rosmalen can occasionally be persuaded to board boats and discuss shipwrecks—MARS the Magnificent was a particular favorite—his true passion lies underground. Diving since the early 1990s, Anton has participated in numerous cave exploration projects, both underwater and in dry caves, across Mexico, Croatia, Spain, Italy, and France. He has taken on various roles, including support diver, push diver, and expedition organizer. Anton was also part of a GUE expedition to search for the shipwrecks of Operation Pedestal.