Surprised by gigantic wave

Your best bet is to try to swim over the wave before it breaks. If this is not possible though then you need to extend your arms and legs away from yourself to spread the impact and keep yourself from being thrust deep into the water. Take a deep breath and wait until the turbulence subsides. Youll get tossed around but try to stay oriented and dont panic. Get back to the surface quickly, breathe, and reassess the situation because you may have to repeat.