Second trumpet, and something like a great mountain on fire was cast into the sea. Something like a mountain, so that would be a triangle shape, not a round shape like an asteroid or meteor. The only thing I can come up with is one of these underwater mountains. It is on fire and is cast into the sea, so some parts of it are above sea level. One of these volcanic islands would fit the bill. The next thing is that it needs to be in a position to sink one third of the ships in that sea. Not every sea, and one third of all shipping in the sea it is in. That means it is in the North Atlantic or Indian Ocean. The Pacific is too big. The volcanic islands in the South Atlantic are not in a good position to sink one third of ships and kill one third of fish with their initial explosion. One of the volcanoes at the northern end of Indonesia and the Bay of Bengal is in the sea? It just does not seem like a big enough event. There are others, but my personal favourite is Ilha Des Flores or Vila Do Corvo, some Portuguese islands right in the middle of the North Atlantic. They are on the edge of a deep trench and could cause a massive tsunami. It is consistent with modern prophecies that have a giant tidal wave hitting the East Coast of the USA and Ireland being hit by a tidal wave that will leave next to no one alive.