What a wanker.

Dropping anchor when a ship is making way , even outside a sea-lane, is a fine way to tear stuff up. those systems are designed to keep a ship stopped. They are not designed to handle use as a speed brake.

Do that sort of thing in a busy sea-lane the sudden loss of speed, loss of control and position could end up as a major collision, fire, mayhem (OMG ... Save my baby), sinking/s, and worse of all ... months and months of talking with lawyers and insurance people. Better to drown, I think.

If he has a 50' yacht what the hell is he doing on a cruise ship? Cruises are not cheap and for that sort of money you could hire a couple of deck ornaments as 'crew'. Pay them right and you can drop anchor any time you want.