The unit will look at all wrecks within 12 nautical miles of the islands

They will map the locations of the sunken vessels and try to establish whether their preservation is under threat.

English Heritage has commissioned the study from Cornwall County Council's Historic Environment Service, formerly known as the Archaeology Unit.

The unit has won a six-month contract to look at all wrecks within a 12 nautical mile limit around the islands.

The archaeologists are also inviting comments on wrecks from the Isles of Scilly Council and local people.

At the moment, a list of about 715 shipwrecks is held by the National Monuments Records Centre in Swindon.

But there are thought to be about 300 more.