A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying goods or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished from boats, based on size, shape, load capacity, and tradition.
The lightship Ambrose LV-78 / WLV-505, now on display at the South Street Seaport, along with the tower that replaced her ( since replaced by another tower, and then a buoy that got run over a few times. I'm not sure if there is anything out there now. )
A lightship is a small vessel with minimal engine power and a stout stable hull, designed to act as an anchored long-term floating lighthouse outside of a harbor. They were generally painted in bright red or orange anti-collision colors. Not that it helped much.
A ferry is a ship designed to transport people or vehicles across the water on a regular schedule. Ferries generally cover only short distances in protected areas and are not designed for the open sea. The distinction between a ferry and a steamer is a blurred one, though, especially in the waters around New York City, where the same company might operate a cross-river vehicle and passenger ferries, and cross-bay passenger steamers, all for the same commuter service. Some ferries even carried rail cars.
A packet ship of the early 1800s. Of note is the way the sails on the mainmast are set backward, against the sails on the fore- and mizzen- masts. Known as "backing", this was how a square-rigged ship "put on the brakes" to slow or stop without actually furling the sails.
Wind power has been used by mankind for millennia. Almost every human culture has constructed sailing vessels of some kind, from crude log or reed rafts to the highly developed wind-jammers of the early twentieth century. Many of these vessels were the most complex and technologically advanced machines of their time - equivalent to our jet airliners.
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.
World War II - USS Blenny SS-324 - 312 ft, 1,810 tons, 8 knots submerged
Everyone knows what a submarine is - a ship that can go underwater. Hardly needs any explanation. Unless you're in the US Navy. By the Navy definition, only their modern, nuclear-powered boats ( all submarines are called "boats" ) are true submarines, designed to operate beneath the surface almost indefinitely. Anything else is merely a "submersible", tied to the surface by the need for fuel and air. Whatever.
Notes: River otters are shy but playful creatures that spend much of their time just splashing around. They don't like human encroachment and are uncommon nowadays.