Re: Lightning ground cable - to where?
you may want to research lightning protection, as much of what mr. honey presents is no longer in vogue, especially the idea of running more cable from the keel back UP to the chain plates...
His comment on static dissipator is dead on. Not so much with ground plates of a square foot or so...you are setting up for a hull breach, should you take a direct hit. The same for using a through hull or anode
Many feel that short of a complete engineered faraday cage, you are better off doing nothing.
Your boat, your call. Best of luck.