Yacht? This thing is 590 ft long! It has a beam of 68 ft! It displaces 18,000 tons!
It is not only far bigger than an Arleigh Burke destroyer, it is also larger than the Zumwalt Class destroyers (which really should be classified as cruisers), and Ticodneroga Class cruisers, and Slava class Cruisers. Only the Kirov cruisers are bigger.
Oh, by the way, it will also do 32+ knots and is designed to cruise at 30 knots.
Supposedly Saudi billionaire, Al-Waleed bin Talal, had it built, at a cost of over $400 million.
I wonder if his personal security contigent had MANPADS and other nice toys on that baby....like say some 14.5mm or 20mm weapons, in addition to small arms.
If I spent that much and was operating such a vessel in any dangerous waters at all, where pirates might be tempted, I know I would make sure I could protect her.