 Salt water provides for greater organic activity than freshwater, and in particular, the shipworm, teredo navalis, lives only in salt water, so some of the best preservation in the absence of sediments has been found in the cold, dark waters of the Great Lakes in North America and in the (low salinity) Baltic Sea (where the "Vasa" was preserved).Diver trails also called wreck trails can be used to allow scuba-divers to visit and understand archaeological sites that are suitable for scuba-diving One excellent example is the Florida Public Archaeology Network's (FPAN) "Florida Panhandle Shipwreck Trail.