HMS Impregnable
Lying just off the Hampshire coast in Hayling Bay are the remains of HMS Impregnable. This 2nd rate ship fo the line was lost in October 1799 when returning from escourting a fleet of ships from LIsbon. Keen to make it back into Portsmouth for a Friday evening the First mate insisted on maintaining a high speed despite nearing shore. Their position had been misjudged and the ship was soon aground in these shoal waters.
Hope of re-floating the vessel continued for several days while the guns and stores were removed. But eventually the breached hull was abandoned. The site was then heavily salvaged.
Survey has revealed the remains of the lower hull covered with concreted blocks of iron ballast bars. Copper fastening pins protrude from the gaps between ballast blocks where timber floors were once positioned.
Surveying HMS Impregnable
This site makes a fantastic dive, in relatively shallow waters (6 - 7 m) it is diveable at most states of the tide. We are using the site of HMS Impregnable as one of our first 'Information for Divers' sites.
The site was revisted during ESolMAP 2004. It appears to have been relatively stable over the year with only a small localised change in the seabed levels. Measurements were taken from designated points on the ballast blocks to the seabed, these records will help us monitor any seabed changes more effectively. We collected seabed samples from two areas of the site, which will be analysed to help tell us more about the environmental conditions and the possible effects these may be having on the wreck remains.
Taking samples on the HMS Impregnable site
The HMS Impregnable site was surveyed by Wessex Archaeology as part of their ALSF/ EH project 'Wrecks on the Seabed.