Maximum Carrying Capacity

[gentoo]

I'm not sure if this is the right place to start this thread, but I'm wondering how to calculate how much weight in provisions and equipment a yacht can carry without seriously harming the stability. The situation I have in mind is an atlantic crossing with four people in a 27ft albin vega. I'm estimating that we'll require something on the order of 2000lbs of equipment and provisions. Cramped living conditions are fine, but I have no idea how much this boat can safely carry and don't know how to calculate it from readily available information on the net. Any help would be greatly appreciated! Jan