So how about one a little bigger...may be 100 ft? The boat is wider, overhead higher, and nothing to hang on to. (Personally, I would like something to hang onto, but what I'm trying to point out is that sometimes our general concept of what is a bluewater boat is a bit limited. Surely, these multimillion dollar boats are more than coastal boats.
Yes, I know what you're driving at; one can be too bombastic. Still, even 100 ft is nothing in a real ocean, you will not be taking leisurely strolls about without holding something - and that is before a real storm arrives. I almost broke a guy's knee last year, being stupid: he was sitting on the step to the cockpit and instead of asking him to move I thought I could sneak past. A freak wave bounced me on top of him - I still recall his screams. The wind might have been, well, just beyond a strong breeze?
Somewhere, there is a video online of a tourist ship, many hundred tons, hundreds of passengers, caught in bad weather along the coast. The bar is smashed, the lounges are cleared and all passengers are sent to their cabins because they cannot keep still in the open areas. Crew are leaping from the one fixed point to the next.
I think you'll find that the multimillion dollar yachts you mention are in fact crewed from one cruise area to the next, with the actual owners rarely boarding except when in port or cruising in nice, smooth waters.