"Some of the stuff produced in the UK would never compete on the world stage if it weren't for the Royal seals or endorsements"
I traveled over and lived in a lot of the World - and I can honestly say I've never heard anyone say that they were buying anything because the UK Royal Family "endorsed" it - you only hear that in the UK.
I suspect that the when the change of monarch comes, hopefully not for a long time yet, the change will make any Royal Yacht totally superfluous.