From the class rules: "A number four jib may be carried provided that it has an LP no larger than 7 feet 7 inches"

Note that a maximum sized #4 can be close in size to a #3 (8'0 - 8'7") and likely not the best thing for offshore or shorthanded sailing. A more appropriate #4 for rough weather would be quite a bit smaller and with a high clew.

The right #4 design and material does depend on your needs. Also you want it to sheet to your existing hardware.

Your friendly neighborhood sailmaker can be helpful here...

--brendan

:: I searched but didn't find anything. Can someone tell
:: me what size a #4 is? any details would be appreciated,
:: preferred fabric etc.