In your 5/05/2024 post still trading, while sailing through as the blood of a dead man? (fivedoves.com) you asked the following questions after first referring to 

Revelation 16:3 And the second angel poured out his vial upon the sea; and it became as the blood of a dead man: and every living soul died in the sea.

Revelation 18:17 For in one hour so great riches is come to nought. And every shipmaster, and all the company in ships, and sailors, and as many as trade by sea, stood afar off,

  18 And cried when they saw the smoke of her burning, saying, What city is like unto this great city!

  19 And they cast dust on their heads, and cried, weeping and wailing, saying, Alas, alas, that great city, wherein were made rich all that had ships in the sea by reason of her costliness! for in one hour is she made desolate.

It says every shipmaster - and all the company in ships, and sailers - and as many as trade by sea.

Are they still out there, at sea, on the oceans that became as the blood of a dead man, still trading with Mystery, Babylon?

Or is the sea upon which the second vial is poured out, simply, as it says, a single sea, like the Mediterranean, Black, Caspian, or Galilee?

But the waters about Mystery, Babylon, at the same time, are not as the blood of a dead man, and are still filled with ships, still trading?

Where their owners are still made rich by trading with Mystery, Babylon, up to the last minute?

The third part of the sea already became blood in Rev. 8:8 and a third part of the ships were destroyed in Rev. 8:9 along with a third part of the creatures in the sea dying. This took place after the 2nd angel sounded the trumpet and a great mountain burning with fire (volcano) was cast into the sea.  I am not sure whether Rev. 8:8 & 8:9 refers to a third of all the seas on earth or a third part of just one sea, such as, the Mediterranean Sea. It would make more sense though if it was 1/3 of the oceans because the Atlantic Ocean makes up 29% of the Earth's surface, and the Pacific Ocean makes up 30% of the Earth's surface.

And if the great mountain of fire sliding into the sea was a volcano, such as, one on the Canary Islands off the Northern coast of Africa that will slide into the Atlantic Ocean and a tsunami travelled westward, it may wipe out all the ships on the Atlantic Ocean or the same thing might happen in the ring of fire in the Pacific Ocean with a tsunami wiping out all those ships. It may not affect the trading or the ships in the Mediterranean Sea if Mystery Babylon is the Vatican city surrounded by Rome or Mecca inland from the Red Sea until later on when all the sea is turned to blood in Rev. 16:3. With everything dying in the sea, there would be a horrible smell. How would people trading on a ship be able to breathe with a terrible stench filling the air?