Captain/Owner Sleeping at the Helm

[Phisher]

I recently crewed on a catamaran from St. Thomas to Ft. Lauderdale. We did a staight shot St. Thomas to Turks and Caicos. I took the Midnight to 4 am watch, which followed the boat owner. On 2 different occasions I show up at the helm for my watch and would have to wake up the boat owner. Each time I woke him he acted as if everything was fine, he would mumble that we are on the magenta line and on course. Whatever sleepy head were my thoughts. This man would not listen to me about several instances and situations. One being the terrible vibration undersail. I questioned why he did not engege the transmissions to the reverse position to stop the vibration. He said that the boat has had that vibration since new (2016 Lagoon 45) and several captains had noted in there logs.(Charter Boat) The vibration was all to obvious that the props were the cause. So I engaged the trannys into reverse BOOM! vibrations gone. I could tell the owner was a little insensed by my observation being correct. Now,how do we deal with know it all captains? Should I have informed the rest of the crew, one being his green wife, about Captain Sleepys issue of falling asleep on watch?