In April and June 1972 Sotheby’s auctioned part of the most valuable antique treasure yet recovered from an historic shipwreck around the British Isles, and yet despite extensive publicity in the months before, in which the value of that part of the treasure was estimated at £ 1OO,OOO, not one museum approached the divers to discover what they had found. Had this been done the museum would have discovered, amongst many other things, fragments of the oldest known octant, predecessor of the sextant, and the first accurate navigation instrument, as well as one or two previously unrecorded silver coins.