Bob, my original intent was to point out that the possesion of alcohol for private consumption is legal.
If the pilot of the craft is operating in a dangerous manner they can be cited, if they are over .08% they also can be arrested.
You're above info. pertains to commercial/ therefore public transportation etc. not a private Houseboat/ Craft.
Have you ever had a drink on a Airline flight?
Why do we push for a designated driver for the intoxicated passengers in a vehicle including boats.
Ask any KDFW officer about this, sit on the front deck with a long neck and they can get you, put it in a cool cup and they will leave you alone, go inside where the PUBLIC can not see it and no problem.