A white yacht seems relevant to the situation over the last twelve months. Able to slip freely from Island to Island and port to port. A vessel familiar to eyes that watched the central sea.Owned by someone with links and accrued power who is aware of the central core of the mystery.
At one time (or more) 'the valuable eye' will have been aboard this vessel. Slipping un-noticed from historic shore to historic shore.
Island small and large from The Straits to The Greek Islands are likely to be ports of call during the time that the hunt was on ... and a safe hiding place was required ....