The Collaborative International Dictionary
Sea pass
Sea pass \Sea" pass`\ A document carried by neutral merchant vessels in time of war, to show their nationality; a sea letter or passport. See Passport.
Wiktionary
sea pass
n. A document formerly carried by neutral merchant vessels in wartime to show their nationality.
Usage examples of "sea pass".
It's not hard to lose track of time completely when watching the sea pass by, especially after it gets dark.