The “Seamark” was built in 1958 by P K Harris & Sons of Appledore (later Appledore Shipyards), Devon and was commissioned by the then Swansea Pilotage Authority. The “Seamark” replaced Pilot Vessel “Roger Beck” which had been serving the Port from 1924 through to 1959, and the “Woodbridge” which started service as a pilot vessel in Swansea in 1951.
In 1959, the “Seamark”, with its distinctive yellow hull with the red stripe and its white superstructure, began serving the Port of Swansea under the Swansea Pilotage Authority. Its distinctive colouring made it easily recognisable as it ventured out to sea in all weathers to meet incoming vessels, and was often referred to as “the banana boat” because of its colouring and its curved appearance from bow to stern.
In 2001 the “Seamark” was retired from service and the “Benson” which for a brief period had worked alongside the Seamark took over the Pilotage in Swansea and Port Talbot. The “Seamark” was taken to Cardiff and moored in the Roath Basin, part of the Cardiff Docks complex and for a number of years, having been repainted black and white, was used by the Sea Cadets and the Maritime Volunteer Service, however, more recently she became unused and rapidly started to deteriorate and was put up for sale.