Here on the SE coast of Africe we speak of "rogue waves" with some equanimity- "they are
out there" seems to be everyone's attitude.
The thing is, they seem to be associated with certain weather
conditions: deepwater groundswells from the South, coupled with wind-over-current conditions (Stiff SW blowing against the S/SE Mocambique current) and we actively avoid passagemaking in those conditions. I guess the way to avoid them is like avoiding tornadoes- just stay out of their side of town when they are likely to be around. Certain seasons seem to be associated with terrible waves in all parts
of the world: get to know when tose seasons are, and what creates the waves, and statistically you should avoid them.
Just in terms of risks, shipping
containers are probably more likely to savage the bottom of your boat then... Now THAT is a scary prospect!