I spent Saturday morning in the "hall" at the sailing club weighing and swinging a Finn. (The boat, not Matti the rotund Finnish chap standing by the door)
One of the curiosities on the Finn class is that there is not only a minimum weight limit (116kg since you asked) but also restrictions on the weight distribution. It has been found that the placement of the weight within the boat make a difference to how it performs and apparently the weight should be at the ends and not in the middle. To measure this, the boat is hung from some hooks in the middle and rocked backwards and forwards. By knowing the radius of the swing (length of the hooks) and the timing of the swings, it is possible to calculate the weight distribution. There is a bunch of complicated maths in there somewhere, but you swing the boat from two different hooks. Measure the average time per swing and plot it on a graph. If it's within the lines, you're good to go. The closer to the bottom left corner, the better apparently.
We only managed to weigh and swing Ricard's boat because the gig is a bit too narrow and needs some revision, but I hope to be able to get my boat re-weighed and swung in the next month or so. It was (believe it or not) and interesting morning and I learned a fair bit about how all of this stuff works in the weighing and placing of weights in the boat.