Divers off the Pembrokeshire coast UK may be about to re-write history after discovering an unidentified shipwreck in 30m. Until now it was widely believed that no ships were lost when the French invaded Fishguard in 1797 – the last foreign invasion of mainland Britain. But items found off Strumble Head appear to be from a large warship dating back to the Napoleonic era. Sub-aqua club members have discovered copper drift pins, large pieces of iron, a swivel gun and three cannons. The Welsh assemblyâs historic monuments agency Cadw and the Nautical Archaeological Society are hoping to send specialist divers to find out more about the wreck next year.