I used to be sea sick, didnt take drugs due to diving and not good for you, was told to drink a pint of milk and eat as much white bread as possible 1 hr or so before getting on the boat.
I have tried this and wasnt sea sick, as the milk neturlizes the acid in your gut and the bread soaks up all the nasties in there
. Tell him hes got to keep going on boats eventually he will get over it
. As every one is different a good breakfast before hand can help, avoid coffee this made me really bad
Tony