As info, some yachts have a support ship that will follow them and carry additional crew, equipment, smaller ship to shore tenders, recreational equipment, jetskis, cars, helicopters, etc. And like
>>1588589 said, the infrastructure and expertise needed to fabricate them is already there. No one wants a flying boat that can't handle rough seas, nor does anyone want a luxury blimp that can only moor in select aerodromes (and also cannot ride out bad weather).
>>1588577>does it solar poweredAbout all that can do is keep the batteries charged up. Solar will never be enough to provide service power for a yacht. A lot of smaller boats actually have small solar arrays to keep a trickle charge going to their batteries, but that's about the limit of what you can get. Large yacht owners (since each vessel is basically bespoke) don't really want ugly solar panels all over their sleek yacht, though. I wouldn't.