A tugboat is a small sturdy and powerful vessel designed to push or tow other vessels and barges
Tenacious
You will see them in every sizable port; smart, businesslike small ships, low in the water and surging out to a large inbound ship. Tugs represent power for pushing and pulling, an engine with just enough hull for adequate buoyancy. Thick fenders for close-quarters work, pushing a big ship alongside the quay against the wind, hauling her off at the end of a towing wire.
The Alexander Hamilton was the last of the steam-powered side-wheel riverboats of the Hudson River Day Line. Built in 1924, she ceased operations in 1971. A well-meaning group pulled the Hamilton from the mud in 1977 and moved her to a temporary berth along the east side of the Navy pier, planning to restore her as a museum. Unfortunately, at the new more-exposed location, the old vessel was sunk and reduced to scrap by a sudden storm in November of that year. The last records indicate that the wreck is still there, and you can even make out the outline on Google Earth.