True or False: A gasket in a water tight door seals against the water tight door?

A gasket in a watertight door indeed serves the purpose of sealing against the door itself. Gaskets are designed to create a tight seal that prevents the passage of water, ensuring that the door maintains its watertight integrity under pressure. This sealing mechanism is crucial in applications where water ingress must be prevented, such as in submarines, ship hatches, or any structure that faces a water barrier. The correct answer reinforces the functional role of the gasket in maintaining the effectiveness of the watertight door by forming a barrier between the door and its frame or the surrounding structure, thereby preventing leaks.