On August 26, 1883, Krakatoa exploded. Before it went, the sea in its vicinity was said to have turned bright red.
I believe this was even part of the movie Krakatoa, East of Java (1969).
Thing is, it seems that the ocean in this area to too deep to allow such a splendid display originating from the seabed. But I will keep your comment in mind, thanks.
An almost acceptable movie, though it didn't do the disaster justice. And the title always bugged me. Krakatoa is west of Java.