Graving docks, floating docks, and ship lifts

What is the difference between a graving dock and a dry dock?

A graving dock is usually a drained fixed basin, while a floating dry dock lifts a vessel; everyday usage often calls both dry docks.

A graving dock is a fixed basin that is flooded to admit a vessel and then drained so the hull rests in a dry working space. A floating dry dock instead submerges beneath a ship and rises to lift it clear of the water. Ordinary usage often calls both arrangements dry docks, so historical and modern labels can overlap. Slipways, marine railways, and ship lifts offer other ways to remove smaller vessels from the water. The distinction matters because each system demands different infrastructure, operating procedures, and limits on ship size.