There is a lot of chaos, uncertainty, imprecision and error in the world, not least in marine weather. When a wave height forecast is given using significant wave height (SWH) of course there are many possible sources of error, but there is no reason to introduce unnecessary errors if it can be avoided. Not understanding or misusing SWH is is an easily avoided error.
BTW the official discover of modern chaos theory was a meteorologist, Edward Lorenz. Lorenz was playing with computer models to simulate weather.
Point being, don’t make things harder than they already are.