Namor's Imperial Craft required a crew of 2 and could comfortably hold up to 8 people. It had VTOL capabilities and could
The Imperial Craft's cabin was air-filled, but had moisture-lined walls which somehow allowed water-breathing Atlanteans to function normally without requiring water-breathing helmets.
During his reign as Atlantean regent, the Sub-Mariner made use of such a vessel as the flagship of the Imperial crown. During World War II, Namor lent the use of his flagship to his wartime allies, the Invaders. The ship was outfitted with a battery of guns that fired intensely compressed jets of ionized water. The water jets were as powerful as machine gun fire and could be used to shoot enemy craft out of the sky. After the war, Namor brought the ship back to Atlantis.