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The Fleet Diving Squadron

Royal Navy divers

Commander Del McKnight RN describes the varied work undertaken by the Royal Navy’s clearance divers

On Horsea Island, on the northern shore of Portsmouth Harbour, lie the dark and murky waters of an old torpedo testing lake. On the edge of that lake sits the home of the Fleet Diving Squadron (FDS). The headquarters building itself contains eight of the ten diving units that make up FDS, with the other two located within the naval bases at Clyde and Devonport.

Operationally focused

Royal Navy divers with their launch RMAS Moorfowl at Loch Striven, after recovering the remains of one of Barnes Wallis’s ‘Highball’ bouncing bombs.

The squadron comprises over 165 highly motivated and dedicated Royal Navy clearance divers, whose training and unique skill set enable them to support UK interests on a global scale, whether that be explosive ordnance disposal (EOD) on land or sea, diving capabilities or engineering support to both the surface and sub-surface flotillas, at home and abroad. In 2017, the squadron was called out on 442 EOD tasks and 11 improvised explosive device (IED) tasks within the UK. The squadron supports a further nine named Royal Navy operations and four defence tasks, with 63 combined UK and global tasks taking place in 2017.

In addition, FDS is increasingly employing mine warfare personnel to man and operate a growing number of offboard systems, such as the autonomous robots that are integral to mine counter-measures efforts, and remotely operated vehicles used for underwater force protection.

The teams

Among the teams that make up the squadron are the three units of the Fleet Diving Group, whose responsibilities include maritime counter-terrorism and mine counter-measures. They are experts in discreet long-endurance swims using oxygen rebreathing sets, often at night, then climbing the sides of ships and offshore oilrigs. Or they may work in shallow water, ensuring that any beach used by the Royal Marines and the Amphibious Task Group is clear of dangerous ordnance, using autonomous systems and hand-held sonar to locate mines and make them safe. These are all arduous tasks that require a huge amount of practice and extreme levels of fitness.

Underwater force protection teams may fly out to join ships overseas. In recent years this has primarily meant supporting Gulf operations, but the Navy divers also participate in numerous exercises over the course of the year, as well as in wider training and development exercises.

There are also two Area Dive Groups, Northern (based at Faslane) and Southern (split between Portsmouth and Plymouth). In addition to supporting the Navy’s surface and submarine fleets, they may be tasked to provide assistance to civil authorities such as the police and the coastguard, and they are on call to supply divers to the NATO Submarine Rescue System (NSRS). Both groups also deploy regularly to areas where old ranges or munitions are found – for instance to the Gower peninsula near Swansea – where they remove or make safe numerous legacy mortar and artillery rounds, many of which are chemically filled and remain quite potent and dangerous to this day.

The tasks – a few examples

Royal Navy divers attending the capsized fishing vessel Solstice, shortly before it sank off Plymouth in 2017. HMS Argyll standing by. One body was recovered.

We recently helped to recover some Barnes Wallis bouncing bombs from the bottom of Loch Striven, where they had lain since World War 2. The loch had been the site of trials conducted for a ‘Highball’ bouncing bomb, the navy counterpart to the RAF Dam Busters’ bombs. The concept was to use it against the German ship Tirpitz that was menacing the Arctic convoys from the safety of the Norwegian fjords. Several bombs were recovered, and they will be displayed at the Brookland Museum in Surrey and the de Havilland Aircraft Museum in Hertfordshire after they have been properly preserved.

Another recent task took us to central London, where a German 500 kg bomb left over from the Blitz had to be removed from the vicinity of London City Airport. Lifting equipment was used to raise the bomb from the seabed, out through a lock and down the Thames, a transit that took in excess of ten hours.

When FDS was asked to help out at an overturned fishing vessel we had to deploy quickly, for it was possible that crew might be trapped inside. Two divers searched the hull, and sadly located a body. They managed to complete the dive just as the stricken vessel sank beneath the waves, proving the danger of the situation.

Some tasks are closer to home – for when HMS Queen Elizabeth made her first entry into Portsmouth in August 2017, it was the responsibility of FDS to ensure that the seabed and jetty were thoroughly searched. Members of the squadron have also been heavily involved in developing the underwater force protection plan for the new aircraft carrier, and have recently sailed with her to the United States to ensure her trials continue as planned.

A challenging career

In truth a hundred different activities could be described, from parachute training to diving on the World War 2 carrier HMS Hermes in Sri Lanka, from numerous IED call-outs to unwrapping fishing net from around a submarine. The Fleet Diving Squadron is an interesting place to work, providing varied employment, not just for divers but increasingly for a range of support staff. Any young man or woman looking for an interesting and challenging career need look no further!

Commander Del McKnight joined the Royal Navy in 1989. Since 2016 he has been Commanding Officer Fleet Diving Squadron.