The weight minimums for some of our classes is so sailors are placed in a class best-suited to their size. All single-hull sailboats heel (tip) in a certain amount of wind. In dinghy sailboats, sailors use their body weight to hike out
and flatten the boat as it moves through the water. Vanguard 15s and Lasers have relatively large sails for some small sailors, therefore there's a weight minimum of 100 lbs. for classes that use Vanguard 15s or Lasers (Junior Jibers, High School, Vanguard 15 Race Camp, and Laser Race Camp). If sailors are too light to balance the boat out with their body weight, they will have a hard time controlling the boat and are more likely to capsize.
Sometimes children have been in Overboard Optis for several years as they do not meet the 100 lbs. weight minimum. Parents wonder why their child can't "move up" to Junior Jibers. The difference between Overboard Optis and Junior Jibers is not that one class is more advanced than another, it's simply that each class sails a different boat to meet the need of different sized sailors. For some perspective, sailors on the SYC Junior Race Team will often sail Optis until they are 14 or 15 years old and weigh up to 120 lbs.