On a boating site, I saw this system:
http://www.locknstitch.com/cracked_e...ock_repair.htm
A lot depends on how much work you want to do, how long you want to be boatless and how much you are willing to spend.
Remember it is a 14 year old engine. If your labor is free (you) then maybe repair is a good idea. But if you're paying for labor, I'd drop in a rebuilt engine.