The simplest answer to the differences between them, is that a ship is a very large watercraft and a boat tends to be smaller. The exact line separating the two types of vessels can vary by regional location, and is a little murky even for old-timers.
To elaborate, a boat is a smaller vessel that typically would not be able to make long voyages at sea. There is an old navy adage, that differentiates between boats and ships. It says that ships are able to carry boats aboard the ship. But a boat is not able to carry a ship aboard.
This is probably a good way to look at it, but you know there are always exceptions.
Difference Between a Ship and a Boat?
For the most part, this distinction depends on two things, the size of the vessel, and does it require a crew to operate and maintain the vessel while at sea.
Ships are also typically equipped with the proper operational and navigational systems so they can operate and travel across seas and oceans.
Smaller boats, generally are not able to match this type of operation.
3 Masted Sailing Ship
In the past, during olden times, a ship may have been referred to a sailing vessel with 3 masts. They were sometimes called a “Tall Ship“. These squared-off marine vessels dependent upon the wind to fill their sails to traverse oceans. It seems, they were quite effective, as most of the world was explored by sailors in three-masted sailing ships before there was engine-powered propulsion.
Examples of Boats …
A boat can take on many forms. Think about fishing boats, sailboats, kayaks, canoes, dinghy, ski boats, and submarines. Yes a submarine is considered a boat.
An aircraft carrier is a ship, and a submarine is a boat.
So, one simple saying, is that “a boat can fit onto a ship, but a ship can not fit onto a boat”.