Hog Island is an island roughly 2 acres in size located approximately 5 mi south of the entrance to Tomales Bay in the West Marin area of Marin County, California. While waters to its west are deep enough for small ships to enter Tomales Bay, at low tide the shallows to the east may be wadeable to the eastern shore of the bay. Unsuspecting vessels hav…Hog Island is an island roughly 2 acres in size located approximately 5 mi south of the entrance to Tomales Bay in the West Marin area of Marin County, California. While waters to its west are deep enough for small ships to enter Tomales Bay, at low tide the shallows to the east may be wadeable to the eastern shore of the bay. Unsuspecting vessels have run aground in that region a number of times. However, as it is some distance from the mouth of Tomales Bay, Hog Island does not experience the large sudden waves that characterize the Tomales Bay Bar entrance region.