The equivalent of roofin or beachin but on a cruise. You go on top of your cruise
ship at night and since there are no lights and you are on the middle of the ocean you can see the entire universe without any light pollution. You chill up there with your
friends, contemplating life, the universe, humanity, and chillin with the
nice cool sea breeze blowing across the ship. This is considered the purest and ultimate form of the roofin, beachin practice/art since there is no light pollution although roofin and beachin can still be performed in areas where there is no light pollution on land. Another term for Cruifin is Cruise Toppin.