A slipway, boat slip or just a slip, is a ramp

Inclined plane

The inclined plane is one of the original six simple machines; as the name suggests, it is a flat surface whose endpoints are at different heights. By moving an object up an inclined plane rather than completely vertical, the amount of force required is reduced, at the expense of increasing the...

 on the shore by which ships or boats can be moved to and from the water. They are used for building and repairing ships and boats

Boat building

Boat building, one of the oldest branches of engineering, is concerned with constructing the hulls of boats and, for sailboats, the masts, spars and rigging.-Parts:* Bow - the front and generally sharp end of the hull...

. They are also used for launching and retrieving small boats on trailers

Trailer (vehicle)

A trailer is generally an unpowered vehicle pulled by a powered vehicle. Commonly, the term trailer refers to such vehicles used for transport of goods and materials....

 and flying boat

Flying boat

A flying boat is a fixed-winged seaplane with a hull, allowing it to land on water. It differs from a float plane as it uses a purpose-designed fuselage which can float, granting the aircraft buoyancy. Flying boats may be stabilized by under-wing floats or by wing-like projections from the fuselage...

s on their undercarriage

Undercarriage

The undercarriage or landing gear in aviation, is the structure that supports an aircraft on the ground and allows it to taxi, takeoff and land...

. The nautical term ways is an alternative name for slipway. A ship undergoing construction in a shipyard is said to be on the ways.