Originally Posted by s/v Beth
The buoys almost always under rate the waves- I think they get pushed under water
They also tend to report the 'current value' of mean
wave height, or some statistical measure, perhaps rms or corrected rms value.
What that effectively means is that many waves will exceed the reported height, and some may be 150% or even 200% of the mean.
It's a bit like wind (as we recently discussed) : landspeople and recreational sailors tend to refer to the highest figure they measure; whereas seastate (and people who know and care about seastate) reflect mean windspeed.
However as sailors, unlike the situation with wind gusts (which don't unduly concern us provided we're appropriately canvassed), it's very much the highest waves which we care about.
I guess we should ideally apply a factor to reported wave heights, based on our experiences with that source and corresponding real conditions.