Just travel with the BC (official sites actually say a photocopy is fine, but you might as well use the certified copy) for this trip, assuming it's fairly soon. It's a simple, short, cruise; you're not taking him to the Congo. (while I normally advocate getting a notarized permission slip, just in case, I also know that it's really unlikely to need the form for a Bahamas cruise)
Even though he's not showing up, it's time to get this done. He's missing, he's not showing up...he's already gone. So make it legal.
Obviously that's not simple, cheap, or immediate. It's not something for before this trip, depending on how long you have.
But definitely pay attention to what Princess Shmoo posted; it's on this page here:
http://travel.state.gov/content/passports/en/passports/under-16.html
While it initially looks like you can't do anything, when you expand the sections and read it all, you see there are options. Since you have multiple missed court dates on his part, there's a paper trail. Start working on all of that.
(I say all of this from the perspective of a kid of two divorces. First stepdad considered adopting us but dad wouldn't give up rights...although that first stepdad turned out to be a huge jerk and I haven't seen or heard from him since 1987, I still kinda wish my dad had given up the rights...I would have been better off without his presence at all in my life (though try to convince a 9 year old me of that LOL)...)