Well, sort off.
Royal Yacht it is not: Prince Harry to sleep on tanker vessel during Caribbean tour
The fact that the Royal Navy has had to make available a tanker which is in short supply demonstrates that a new royal yacht that is fit for purpose for promoting trade is desperately needed by this country."
Must be good for some Admirals promotion chances, I could imagine the conversation
"Excuse me we need a ship for a Royal tour"
"No problem, let's see what's available, Tug, Lugger......ahhh Tanker, no problem Sir, we have just the thing available."