I have LIVED the J-24 fairing experience. I was forced to do it DIY as my boat was destroyed by Andrew, and I ended up with a J-World boat that was painted with bottom paint, and the keel was just as it came out of the factory. Some shape on one side, AWFUL on the other. There are also articles written on the subject of keel fairing. I am NOT one of the proponents of moving the keel. (We didn't have the time either) In the J-24 at that time, the minimum thickness table of offsets in the class rules resulted in a decent shape. I expect that the J-30 is similar. What you do need is a comfort level working with battens to loft a fair curve. If you are not comfortable with lofting curves, I do not recommend a DIY attempt to fair the keel. Take your time.
While I am sure my keel wasn't pretty, it did measure in, and it was very fast.
