Det Ch Insp Sean Memory, who is leading the search at that site, said officers had received "relatively specific" information from a man held in connection with Miss O'Callaghan's death but that no remains had yet been found.
The Billy Deacon Search and Rescue Memorial Trophy was established in memory of a Coastguard winchman who lost his life during the rescue of 10 crew members from the Green Lily off Shetland in November 1997.
The search engine has made finding information so easy that we no longer have to rely on our memory or experiences as a starting point for our investigation.