Fishermen gathered and burned Casuarinaceae's leaves around those vessels in order to deal with shipworm that bored into them.
Salt water provides for greater organic activity than freshwater, and in particular, the shipworm, terredo 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).