{4} And the second angel poured out his vial upon the sea; and it {a} became as the blood of a dead man: and every living soul died in the sea.

(4) The history of the second angel, who troubles and molests the seas, that he may stir up the conscience of men sleeping in their wickedness; Re 8:8.

(a) It was turned into rotten and filthy blood, such as is in dead bodies.

Scofield Reference Notes

Margin angel

See Scofield Note: "Heb 1:4".

Revelation 16:3 Parallel Commentaries

Can Our Dead Speak to Us?
The ministration of holy angels, as presented in the Scriptures, is a truth most comforting and precious to every follower of Christ. But the Bible teaching upon this point has been obscured and perverted by the errors of popular theology. The doctrine of natural immortality, first borrowed from the pagan philosophy, and in the darkness of the great apostasy incorporated into the Christian faith, has supplanted the truth, so plainly taught in Scripture, that "the dead know not anything." Multitudes …
Ellen Gould White—The Great Controversy

Opposition to Messiah Ruinous
Thou shalt break them with a rod of iron; Thou shalt dash them in pieces like a potter's vessel T here is a species of the sublime in writing, which seems peculiar to the Scripture, and of which, properly, no subjects but those of divine revelation are capable, With us, things inconsiderable in themselves are elevated by splendid images, which give them an apparent importance beyond what they can justly claim. Thus the poet, when describing a battle among bees, by a judicious selection of epithets …
John Newton—Messiah Vol. 2