The London maritime market of insurers has declared all sea waters of the Russian Federation a "military zone" (not only the Black Sea, but also the Baltic and the ports of the Far East).
What is London Marine Insurance Market?
It is the largest market in the world (about a third of the insurance market share of all merchant ships in the world).
It was there (at Lloyds) that this market originated in the 17th century and it is he who sets the rules for the whole world: model contracts, insurance premiums and much more.
What does it mean to declare maritime territory a "war zone"?
Now, when a ship is about to enter such territory, the owner of the ship must notify his insurer and pay a special "war premium".
Such premiums reach up to 5% of the cost of the entire vessel. For example, a typical ship costs $30 million and the insurance premium to enter the "war zone" reaches $1.5 million.
That is, to justify this, the ship must be loaded with something super expensive (such as microchips or drugs).
Therefore, not a single ship owned by companies from rich countries will simply go there - it is unprofitable.
This news makes it virtually impossible for Russia to trade with a very large part of the world.
It is to be expected that other large markets (primarily Bermuda and Switzerland) will soon follow suit.