Expositor's Bible Commentary Commentary Revelation 8:9

"and there died the third part of the creatures which were in the sea, [even] they that had life; and the third part of the ships was destroyed." — Revelation 8:9 (ASV)

The second trumpet. A huge blazing mass like a mountain is thrown into the sea and turns part of iy into blood. This suggests the first plague, when the Nile was turned blood red and the fish were destroyed (Exodus 7:20–21; cf. Zephaniah 1:3). Reference to the destruction of ships shows the intense turbulence of the sea.