My brother in law is the same. He was keen to head out to do some reef fishing, so I loaded the boat and off we went. The conditions were glass out, he was enjoying the ride out, as soon as the pick went down, he turned that greenish colour. From then on he spewed non stop, couldn't even open his eyes. As frustrated a I was, I pulled the pick and took him back to the ramp (after an hour or so of fishing). I then headed back out with my oldman.
Yeah must feel terrible being in that state. I kept saying "you'll be right". He pretty much begged to go back in. My oldman reckon he would have left him on an island till we were done lol. I think bringing the person home would be the best move as the day is kinda ruined when you have a green zombie on board..