Don't know much about Georgia law. But, it is the only state I know of that refused to recognize a Florida power of attorney for temporary custody of children. For what claims to be a general durable power of attorney that will meet Georgia requirements, go here:
Georgia General Durable Power of Attorney for Property & Finances (Immediate) - Free Legal Form
Not sure what you have in mind by "in the event something happened", but it sounds like something that might inspire more than just concern for the boat by your "wife/partner".