Sounds like a class that already exists...maybe a foot shorter.
Make that "7 inches shorter" instead of the 12 inches that go into a full foot. The class name may use the number 16 but the hulls are actually a bit longer than that.
The name F16.42 didn't sound as catchy as F16.
Wouter
Wouter Hijink Formula 16 NED 243 (one-off; homebuild) The Netherlands