Safe capacity varies with many factors: the size of the crew members, their experience, the weather, the conditions in which the boat is used etc. For example, in good weather, an experienced crew of three or four can safely use our D4 in dinghy service but a pair of inexperienced heavy weights will be in danger in the same conditions.
Our study plans specify what we consider to be the capacity under average conditions. Ultimately, the skipper must decide what is safe capacity considering all of the above.
We help you in specifying the PPI for some of our small boats: this means the Pounds Per Inch of Immersion. In other words, how many lbs. it takes to bring the waterline up one inch at the designed displacement.
Another good way to estimate capacity is to take the main dimensions listed on our web pages and trace an approximate outline of the boat on the floor. Imagine your crew in that space.
For outboard powered boats, we use the USCG capacity calculations and usually announce a lower figure to be safe. BTW, there is no requirement for a capacity tag for a home built boat and there is no USCG capacity tag requirement or standard calculation for sailboats.