How do Muslims working on ships that sail for varying distances pray and fast, taking into account the scarcity of water allocated for ablution and the limited times it is available, whether the ships are far from land or close to it (less than 80 km)?

It has been established by the majority of scholars that the legal travel distance for which prayers may be shortened is 83 kilometers, whether by land, sea, or air. The traveler is subject to the rulings of travel, including shortening the four-rak'ah prayers, combining prayers, and breaking the fast. If ships do not reach this distance, their occupants are considered residents. However, if they reach the distance for shortening prayers and stop for 24 hours, their occupants are travelers. Seawater is purifying, and it must be used for ablution unless it is impossible to access it and the water is exclusively for drinking, in which case there is no make-up prayer for one who cannot find water or pure earth (for tayammum).