The campaign has laid massive minefields across large stretches of sea. Knowing their location helps friendly forces but does not eliminate the problem for trade, because merchant traffic still needs routes through the same waters. The game simplifies the consequences, and such blanket mining becomes impractical once the volume of commerce is considered. A defensive barrier must obstruct the enemy while leaving friendly naval and commercial movement workable.
Notable Point · 1:44:56-1:50:17
Defensive minefields still need routes for friendly commerce
Large defensive minefields can impede an enemy, but the same barriers become impractical when a navy must keep dense friendly commerce moving through the area.