All kids line up in front of the leader who calls terminology for their actions, as follows...
Captains coming - all run back to the centerline and salute to the Leader calling out 'Aye Aye Cap'ain' (Scout salute of course)
Port , Starboard, Bow and Stern - all kids run to the relevant place relative to the leader, who is at the Bow.
Scrub the deck - onto hands and knees and make scrubbing motion.
Cannon Ball - duck down to avoid the shot.
Submarine - lie on back with one leg up as a periscope.
Stormy waters - wave and sway with the 'effect' of rough seas.
Climb the rigging - make motions of climbing a ladder.
Crows nest - on the lookout, with Telescope or hand over eyebrows.