Hull (water & space craft)

A hull is the watertight body and frame of a ship or boat or the airtight shell and frame of spacecraft.

In watercraft, above the hull is the superstructure and/or deckhouse, where present. The line where the hull meets the water surface is called the waterline. The structure of the hull varies depending on the vessel type.

For spacecraft, the hull is the sheath applied to the frame with the intent to make it airtight.