YSK: If you are at the beach and are being pulled by a current into deeper water, swim parallel to the beach to the right or left, toward the white caps of the breaking waves to free yourself from the riptide.
from /r/YouShouldKnow
YSK：如果你在海滩上，被水流拉到更深的水域，请平行于海滩向右或向左游去，朝破浪的白帽方向游去，以使自己摆脱激流的影响。