Good thinking, which doesn't make the size of the Baltic Sea comparable to the size of a city, nor the costs of a fleet of cars with a single driver comparable

Good thinking, which doesn't make the size of the Baltic Sea comparable to the size of a city, nor the costs of a fleet of cars with a single driver comparable to the costs of a fleet of ships with full crews. It's tempting to say "if it's such a problem why don't they just monitor better?", but the ocean is vast.