Huge ocean waves, tcunams and flooded islands

In my vision I saw a calm ocean, after a while I saw how the water began to ripple very strongly and violently. Then I saw the water begin to rise so high that I could not see the clear operation. For once, I saw a huge wave falling to the ground, and quite fast. I saw islands that were flooded by the wave. When the water calmed down, I could see nothing, no island. Just water.