Seakeeping ability or seaworthiness is a measure of how well-suited a watercraft is to conditions when underway. A ship or boat which has good seakeeping ability is said to be very seaworthy and is able to operate effectively even in high sea states.
USS Chemung (AO-30) refueling USS Hooper in heavy seas
USS Santa Fe (CL-60) rolling about 35 degrees to starboard as she rides out a typhoon
USS Waldron (DD-699) pitching her forefoot out of the water, while operating in heavy Atlantic seas
A watercraft or waterborne vessel is any vehicle designed for travel across or through water bodies, such as a boat, ship, hovercraft, submersible or submarine.
A dinghy
A 17th-century sailing raft in Paita harbour (Peru).
A Severn-class lifeboat in Poole Harbour, Dorset, England.