This is an EASY problem to resolve. Just put twenty pounds of beer on the lighter side of the boat. Of course, your crew will then want to stay on that side of the boat. So then you will need to put the crew's equivelant weight of beer on the opposite side of the boat. But, of course with that much beer onboard, you may attract pirates. If more than 38 pirates board your Hobie-16, it will sink. A Hobie-16, as we all remember from past discussions on the "old forum", can hold 40 people before sinking.
Oops! Make that 37 pirates. The beer weighs the same as an extra person.