Floating docks are platforms or ramps that can be submerged to permit the entry and docking of a ship. Floating docks are known as 'pontoons' in some regions of the world. A floating dock is connected to the shore with an inclined surface resting upon the dock on rollers. These rollers permit adjustments for the vertical motion of the docks, which are held in place by anchored cables. Floating docks are often seen in small boat marinas. They keep a fixed vertical relationship to watercraft secured to them, independent of tidal, river or lake elevation. Several of these docks are joined to accommodate a larger craft.

Aluminum floating docks are a commonly acceptable variety, because aluminum is splinter-proof, does not rust or rot and does not warp and crack with age. These products will survive the elements year after year despite the climate. They exhibit amazing flexibility and retain their shape and strength in rough waters.

In a maritime dock, floating docks are used to lift a ship from the water for repairs; these are known as "dry docks." This also allows ships to be launched in a gradual fashion, compared to the gravity-assisted launches of the past. Dry docks features concrete, steel or wooden posts called "blocking." Conforming to the shape of the hull, these posts hold the craft erect when the water is drained from the dry dock.

Tugboats help ships enter into a floating dry dock. There are hydraulic gates, also called valves, which can be opened to permit the chambers to fill with water.

When this occurs, the dock floats lower in the water. The opposite action makes the dry dock rise in the water.