They won’t be doing much navigating without rudder control unless the hijackers have enough hands to crank the emergency steering for some extended period. Not to mention enough spare handheld batteries to keep talking until the CG shows up.
The only way I could see it happening is if the entire crew was part of the plan. Also, I doubt the ETO would be of much use anyway since most of them are just IT and AV guys in real life and probably couldn’t help much with the engineering stuff.
What is the point of hijacking a yacht anyway? If it’s a big boat and the boss is onboard he probably has his security guys onboard as well and they aren’t going to take kindly to a mutiny.