In a single version, a minnow can't be tagged if she is absolutely beneath the water. In that case, the shark can both watch for the minnow to surface for a breath, or the shark can try to pull her to the floor to make the tag. One particular person is designated to be "Marco." That person should close his eyes and attempt to tag the rest of the folks in the pool. If a minnow is touching the agreed-upon protected zone (just like the pool drain or diving board), the shark cannot tag it. A rooste...