Players: 6+
Equipment:  Swimsuits and a Pool.
Winning Objective:  None.  Just try not to get tagged.

Description:  One person volunteers or is selected to be ‘it’ first.  The person that is ‘it’ closes their eyes and keeps them closed, and a second person turns them several times in the water to throw off their bearings.  The rest fan out in the designated area.  Every time the person that is ‘it’ yells, “Marco”, anyone that is above water (rather than swimming underwater) is required to reply with, “Polo”.  The person that is ‘it’ repeats this as often as possible, in an attempt to home in on someone to tag by the sound of their voice.  If they tag someone, then play pauses while the new person replaces the previous person as 'it' and moves to the middle, closes their eyes, and gets spun.

Variation #1 - Some play that at no time is anyone allowed to exit the pool.  But, if exiting the pool and jumping in is allowed, then at any time the person who is ‘it’ thinks someone is out of the pool, they are allowed to shout, ‘OUT’ and anyone out of the pool is automatically ‘it’.  This is to keep players from using a quick exit from the pool to escape the person that is ‘it’.

Variation #2 - An earlier variation was that the person with their eyes closed could swim to and edge of the pool and place their hand on the ground outside.  If anyone was caught outside the pool, they became "it".