Three Hobie 18 Women's World Championships were held in the U.S., and they were all bring-your-own boat regattas, and all the boats were weighed at every event. I know that at the last one, in the early 90's in New Jersey, the difference in weights was as much as 30 pounds.

And the age of the boat does not necessarily mean it will be heavier, either. Boats from different years or eras were built heavier or lighter. Our boat was the lightest one there, at only 3 lbs over minimum weight, but I think it was also the oldest boat there.