Robert Prowse, 20, was on the Purbeck Isle along with David McFarlane, 35, and Jack Craig, 21, when it sank off Dorset on 17 May 2012. All three men died. Mr Prowse's body has never been found.
Isle of Wight, said the print of the hind foot was "comparable to those found on Purbeck, where the stone would have originated". He added: "It is certainly what we call a tridactyl footprint ...