A tugboat was a type of large boat used by people from before the Great War.
Tugboats appear frequently in the Tidal Basin, Potomac River, and some small lakes. They can also be found in the Fallout 3 add-on Point Lookout. Many of these wrecked tugboats have loot hidden inside of them. (usually in the form of a med-kit or ammunition box)
Fallout: New VegasEdit
They only appear infrequently in Lake Mead, and never house any loot. Another tugboat can be found inside the collapsed overpass tunnel in Lonesome Road. For this particular tugboat, there is no given reason for why it might have been left there.