"A floating mine that just happened to drift to exactly the perfect spot on a ships machinery space, so as to do disabling damage with minimum risk of oil spillage. Sounds improbable doesn't it."
depends on th e number of mines, the number of ships... all sorts of variables. Thats why you use mines - they're not certain on an individual basis but statistically they are very cost effective
You'd expect a attacker manned or under remote direction to go for something a bit more valuable or newsworthy than a general cargo ship flagged in Pananma