Joe,

You are correct, F16 allows 1-up and 2-up sailing as the "formula" pertains to the boat and not the crew. There is no minimum crew weight, the only stipulation is that the crew can right the boat without any outside assistance from RC, rescue or other entity. When I sail 1-up I have to take along a righting bag (I only weigh 150 pounds). See www.formula16.org for more info on the rule set.

The F18 rules do have a minimum crew weight and is optimized as a doublehanded boat. Probably stipulates 2 people on board (not sure abt that). You could sail it in Open, but not at any F18 events and remain in class.

It would be interesting to see if 1-up sailing ever crossed the designers of the F18 rule set. Who were the designers of the rules?