In the world of special forces, a unit is considered one of the deadliest and most capable.

At first glance, you will think of the Navy SEALs, Delta Force, SAS, but these warriors are relatively unknown publicly. They are known as Special Boat Service or simply SBS. The SBS operates as the UK Special Forces alongside the Special Air Service (SAS), Special Reconnaissance Regiment (SRR) and Special Forces Support Group.

The creation of the SBS

It was one man's insubordination and ambitious decision that led to the creation of the Special Boat Service. A commando officer, Roger Courtney, had learned to cross hostile territory quickly and quietly while paddling from Lake Victoria to the Nile on big game hunting expeditions in the 1930s.

When war broke out in Europe, he returned to the colder climes of Scotland to defend his country. Having failed to convince his superiors with his folding kayak brigade scheme, he decided to demonstrate its advantages by paddling to HMS Glengyle, which was at anchor in the River Clyde.

Courtney allegedly boarded the ship undetected, wrote his initials on the captain's door, and stole a deck gun cover which he delivered to his surprised superiors as they dined at a nearby hotel. He was promoted to captain and put in charge of a dozen men.

The potential of British amphibious special forces came into its own in 1942 when Churchill demanded the closure of the Nazi-occupied port of Bordeaux, which housed German U-Boats and merchant fleet.

Five teams of what would later be known as the Cockleshell Heroes sailed up the mouth of the Gironde in their canoes, although only two of them reached port. There they attached limpet mines to the moored ships – sinking one and destroying four others.

Despite the loss of life – only two escaped, six were executed and two drowned – Churchill sealed their reputation by claiming the men had hastened the end of the war by six months.

Much of the wartime Special Boat Service (SBS) operations took place in the eastern Mediterranean and Adriatic, though it was not always glorious. Her participation in the ill-fated Operation Anglo, in which eight SBS officers sought to destroy German and Italian bombers on Rhodes, inspired the film They Who Dare but having been so invested in it, she was exhausted to eventually being absorbed into its better-known sister unit, the SAS.

The revival of the SBS

As the tide of war turned in favor of the Allies, the new SBS, with its emblem of frog paddles and parachutes, helped push back the Axis powers in Italy and later Asia. After the war, the unit was active in Palestine and Korea. Among those who served the unit in the Far East in the 1960s was a young officer called Paddy Ashdown.

SBS divers also spied on Soviet ships and replaced Spetznaz, their Soviet counterparts, in training operations with the SAS. One of his most famous missions took place in 1972, following the Black September attacks on Jewish targets at the Munich Olympics, when officers parachuted into the Atlantic to search QE2 after the captain learned that there was a bomb on board.

The organization has also taken responsibility for protecting Britain's offshore oil rigs and nuclear power stations.

The SBS was the first unit to be sent to the Falkland Islands in 1982, earning it a boast of its superiority over the SAS. She helped secure South Georgia and played a leading role in the final assault on Port Stanley. A decade later, having been put on standby to rescue the "human shield" hostages held by Saddam Hussein in Iraq, the SBS was once again the first British force on the ground. A 36-man team dropped by helicopter into the desert outside Baghdad destroyed underground communications for the fearsome Scud missiles.

In 2000, the SBS also rescued a group of British soldiers kidnapped by the West Side Boys from Sierra Leone. But less comfortable times are ahead, as Britain's military role overseas has increased after 9/11. In Iraq, its officers were accused of having "panicked and fled" in the face of enemy fire during one of the most intense engagements of the conflict.

This dispute overshadowed the successful operations that prevented the burning of Iraqi oil wells. However, the unit took the lead in special forces in Afghanistan, helping to secure the Bagram airfield before joining its American colleagues in hunting down al-Qaeda and Taliban leaders. Today qualified 'canoe swimmers' train at Poole in Dorset under the operational command of the Director of Special Forces. Four squadrons are deployed across the British Army.