But the Royal Navy has far more at its disposal than ships in its surface fleet.

Prince Harry discovered what else it had to offer when he visited the city yesterday in his first engagement as Commodore-in-Chief Small Ships and Diving. In his new role the Prince is now the figurehead of the Royal Navy's mine warfare, fishery protection, patrol, survey and fleet diving squadron.

The squadron may not have the same high profile as the surface fleet, but it plays a vital and varied role.

This ranges from preparing beaches for amphibious assault and protecting our waters from poachers, to defusing unexploded bombs and even dealing with terrorist strikes.

Last year the Fishery Protection Squadron, which patrols Britain's seas and waterways, boarded 1,246 suspect vessels and detained 19 boats that were discovered to have broken fishing quotas.

The work of the Fleet Diving Squadron varies from repairing damaged ships underwater to bomb disposal, whether it is a Second World War bomb dropped by the German Luftwaffe in 1940 or a suspect package, such as letter a bomb.

It also includes the Royal Navy's Surveying Service, which has been operating throughout the world since the formation of the Hydrographic Department in 1795.

It is responsible for carrying out hydrographic and oceanographic surveying.