A pint jug or mug is 3/4 filled with beer and placed in the middle of the table. A person is nominated to provide the first 'depth charge' - this could be a shot of whiskey but it must be in a small shot glass that can be 'floated' in the beer mug. This is fairly easy to set up.
Play then goes around the table, with each person adding drink to the depth charge. The depth charge will sink deeper into the beer. The person who sinks the depth charge must pull it out of the beer quickly and down it, and purchase the next depth charge.
Anyone caught nudging the table must down the charge. Also, it is best to nominate when the last game is because the unfortunate person who sinks the charge will have to down the charge and the beer mug contents (fairly rancid after a few games).