Just to clarify a few points.

There has always (for 15 years at least) been a box to tick on entry forms for states and national titles for boats over 65kg. There are separate prizes for the heavier boats and they can also win overall (and sometimes have done).

The heavyweight prizes were actively raced for but the numbers of boats over 65kg has continued to drop to the point where there is only one or less turning up. In that case no prize is awarded.

The minimum weight of the boats hasn't changed, only the method of weighing (and even that was 25 years ago). The heavy boats are heavy because they were built that way or have absorbed water, been repaired and got heavy over the years.