According to Matt Lake in Weird Maryland, two perch fishermen, Francis Klarrman and Edward J. Ward, in 1943 spotted something in the water near Baltimore. This thing was about 75 yards away, at right angles from our boat. At first it looked like something floating on the water. It was black and the part of it that was out of the water seemed about 12 feet long. It has a head about as big as a football and shaped somewhat like a horse’s head. It turned its head around several times—almost all the way around.” A photograph of an unknown sea creature taken by Trudy Guthrie in 1980 was later identified as a manatee from Florida. Manatees are unusual this far from Florida. A manatee nicknamed “Chessie” was rescued from the Chesapeake's chilly water in October 1994 and returned to Florida, but has revisited the Chesapeake several times since then. It was photographed in the Patapsco River in 2010 (unconfirmed) and near the shore of Calvert County on July 12, 2011. The more recent photograph was confirmed by U.S. Geological Survey biologists. Unlike the reports of a serpentine creature, manatees do not swim undulating from side to side.
In 1982 Robert and Karen Frew supposedly videotaped Chessie near Kent Island Their video shows a brownish object moving side to side like an aquatic snake.
The last notable sighting of the beast was in 1997, off the shore of Fort Smallwood State Park, very close to shore. The legend of "Chessie" is very similar to, and was likely inspired by, that of "Nessie", the Loch Ness Monster.