Late period sailing ships (around 1800) had potable water supplies and also pumps, at least some with wooden impellers. Water must have been stored low to keep the center of gravity low. What source of power was used to pump water and what kind of plumbing features did sailing ships have?
Around 1800, you would have started to see the introduction of iron storage tanks for water, which would have replaced multiple wooden barrels in the ship's hold. By weight and volume, drinking water was the largest resource carried on a sailing ship - on long voyages drinking water could amount to several hundred tons.
Drinking water wasn't pumped around the ship, it would be decanted into smaller barrels which were manually carried around the ship, to the galleys for cooking and in larger barrels on the deck for the sailors to drink from.
The stored water supply could be supplemented by distilling seawater. Distilling units were in use as early as 1684 but even by 1800 the designs were still fairly inefficient. The distiller would be attached to a tank of seawater over the ship's stove. Steam from this heated tank would pass along a copper or brass pipe which ran through a tank of cold seawater. This would cause the pure(er) water to condense for collection in a tank or barrel at the end. Obviously, the process could only run when conditions allowed the ship's stoves to operate (and fuel was limited) so this was not a constant source of clean water.
Even without being damaged, wooden ships tended to collect rain and seawater. This would find its way to the lowest parts of the hull. The purpose of the ship's pumps was to draw this water out of the hull. This would either be pumped straight over the side, or the water could be used for purposes such as washing down the decks (and then swept over the side).
The pumps were manually powered, which meant that ships that had suffered storm or battle damage would find the crew needing to man the pumps for hours on end to keep the ship from sinking. The short runs of pumbling for these pumps (and for drainage from the decks) would be mainly lead and leather pipes, with copper or brass in some places.
sources: The Arming and Fitting of English Ships of War, 1600-1815, B. Lavery (Conway, 1987)
The Construction and Fitting of the Sailing Man of War, 1650-1850, P.Goodwin (Conway, 1987)
As of 1800, they didn't have any plumbing as we know it. The main purpose of the pumps was pumping out seawater that had leaked into the ship: ships always leak.
Drinking water was stored in barrels that were brought on board ship full, either at dockside or by being hoisted out of boats. Yes, they were stored low in the ship. A barrel was brought up for use by being hoisted out of the hold.
Source: Nelson's Navy, Brian Lavery, among other books.
By the middle of the nineteenth century, plumbing systems were starting to develop. HMS Terror and HMS Erebus had steam heating and water distillation systems for Franklin's arctic expedition of 1845.