What makes it official is that all four boats will comply with 3,80 m length limit. A hammer in my hands only serves to open a hole in the head to make room for all that data.

I totally forgot about feathering. Optimists feather their sails when being towed and when rigging. Lasers do it when rigging. This is a usefull feature even for kids who prefer to wait in the capsized boat when things get rough (for quietness).

While we are at it, Optimists around here use a snap shackle (or similar) to fast-release the mainsheet block from the boom to feather. I guess we should copy this feature.

I like Wouter's mast support system. It makes sense from the structural point of view and others. My daughter justified her preference for the chined hull shape because "it is easier to grab in order to climb back to the boat". Those bars certainly help too. Also, the capacity to feather makes it easier to rig and tow. Both are important for kids.