I've had two near misses.

One was a cabin crusier pulling a water skiier,
so he was not looking where he was going.

Second was a cigarette boat going what 50+ from
who knows where, who was talking to his bikini
clad girlfriend, when he saw my boat at the last
moment, turned and I saw his props come out of the water.

The first mishap I took evasive action,
the second was good luck.