Probably whaling or salmon fishing ships from when this estuary was a major wintering spot for the ships in the late 1800s.
"Evidence of sunken wooden ships has been found in the mud around the island-- remnants of the time when these protected waters served as a winter moorage for sailing vessels and a “graveyard” for squareriggers."
Sea - Shipwrecks
Links: www.google.com
By: kjfitz