Boat Builder Central - Builder Forums

No need for a picture. That looks just about right
You could go a little more if you still feel rough spots but not very much more.
If you want to see some perfect sanding look at Cracker Larrys GV-18 thread.

Also look at Richards FS-18 Bare Bones. Page 13. I have seen his work up close and personal and could not find a flaw one in it