If professionals who's careers depend on catching fish use FFS then that's what I'm using. Might be too simple of a philosophy but makes sense to me.
Hitting submerged railroad tracks, you Ontario guys know what I mean, yeah it was my fault, got distracted and disoriented and wasn't looking at my GPS. Thought I cleared them and was slowly idleing around an island, all of a sudden S*&$# !. Insurance paid for a new lower unit, SS prop and a complete trim unit, the boat was only 3 months old. Nice boaters put up warning floats near the tracks and the local marinas take them away, BASSTARDS !
Hitting a submerged stump.