Orkney diver death probably caused by boat propeller

Fishing boat Karin acted as a diving support boat

The death of a recreational diver off Orkney was "almost certainly" the result of being struck by a boat's propeller, investigators have said.

Diver Paul Smith, 70, from Greater Manchester, was reported missing after a dive to the wreck of German battleship SMS Markgraf and later found dead near the island of Cava.

Investigations by the Marine Accident Investigation Board (MAIB) are ongoing but they have issued a bulletin describing what happened and setting out safety recommendations.

The MAIB said an effective lookout and frequent communication is needed when vessels are operating near people in the water.

Mr Smith and a dive buddy had been exploring the wreck of German battleship SMS Markgraf, which lies at a depth of 45m in Scapa Flow on the morning of 28 September 2023.

The divers were on their final decompression stop three metres below the surface when the diver was struck by the rotating propeller of the support boat Karin.

Their presence was shown on the water's surface by a delayed surface marker buoy (DSMB), with the line connected to Mr Smith's dive vest.

The buoy was visible to a second dive boat waiting on the other side of the wreck site but was not seen by the crew of Karin, which motored over the buoy.

Scapa Flow, off Orkney, is one of Europe's premier wreck diving sites

The bulletin said: "The crew of the second dive boat saw the DSMB disappear under Karin. Subsequently one of the two divers failed to resurface.

"The coastguard was notified and an extensive two-day air and sea search of the area was conducted, but without success.

"The missing diver's body was found three weeks later following a seabed search conducted by a local survey vessel using side-scan sonar. A specialist team recovered the diver's body from the seabed."

The MAIB bulletin makes a number of safety recommendations in light of the incident, including the need for boat crews to maintain a lookout when operating in areas with people in the water and the need for them to maintain "detailed and frequent communication" with other boats in the same area.

The MAIB also recommends that the British Diving Safety Group, which brings together diving organisations across the UK, shares the bulletin within its membership, particularly to raise awareness of the hazards of attaching DSMB lines to their body or clothing while underwater.

More than 50 German ships were sunk in the waters off Orkney to prevent them becoming spoils of war on 21 June 1919.

During the 1920s and 1930s, many of the ships were lifted from the sea bed by commercial contractors and broken up.

Since then it has become one of Europe's premier wreck diving sites and the seven ships that remain are now classed as scheduled monuments.