Nicola Clay, the PLA's own environmental scientist, worked closely with Dr Anthony Firth of Wessex Archaeology at every stage to ensure that the wreck site was properly investigated and the remains safely brought ashore.

Scientific analysis has dated the timbers to 1574 and indicate that Essex was the original source for the wood. That analysis, the type of construction and details of the four cannon recovered confirm the vessel as an armed cargo vessel of about 30m in length and of British origin. The bow section recovered is believed to be a unique find and along with a well-preserved section of the ship's side is a rare example of shipbuilding of the period. Four cannon were among the artefacts brought to the surface, including one rare example of a weapon bearing the insignia of Sir Thomas Gresham, a gun manufacturer and member of the court of Elizabeth I.

Dr Firth who headed the archaeological teams said: 'This is a very exciting discovery. Although it is early days in unravelling the ship's story, it is clearly an important discovery in increasing understanding of late 16th Century English shipbuilding and also trade and transport on the Thames'.

The timbers have been kept immersed or sprayed with water since being recovered in order to inhibit further deterioration and are to be handed over to the Nautical Archaeology Society at Portsmouth.

There they will be totally submerged in Horsea Lake where they will become permanent underwater exhibits and be available for future training of Marine Archeaologists.

The PLA has now cleared the site and dredging of the Princes Channel can proceed when it is deemed expedient. An unprecedented record of wrecks and obstructions has been complied by survey teams, scientists and experts from the port authority.

A wrecks database is maintained, listing 800 obstructions charted in the Thames Estuary and 600 wrecks or associated debris, most of which are located well away from the designated shipping channels.