Revelation 16:3
And the second angel poured out his cup on the sea; and it became blood, like that of a dead man: and every soul in the sea died.
Revelation 8:8-9
And the second angel sounded; and, as it were, a great mountain, burning with fire, was thrown into the sea: and the third part of the sea became blood.
Revelation 11:6
These have authority to shut heaven, that it may not rain in the days of their prophecy; and they have authority over the waters, to turn them to blood, and to smite the earth with every plague, as often as they wish.
Revelation 10:2
And he had in his hand a little book opened; and he placed his right foot on the sea, and his left foot on the land;
Revelation 13:1
{ And I stood on the sand of the sea, and saw a beast coming up out of the sea, and he had seven heads and ten horns, and on his horns ten diadems, and on his heads names impiously irreverent.}