As the Declaration of Independence clearly states, all men are enodowed with certain unalienable rights, among which are "life, liberty, and the pursuit of the world's longest zip line over water." And since we're not one to go against THE DECLARATION OF INDEPENDENCE, we pursued the latter until, bing-bong-bing-bong, we found it.
Located on a private part of Haiti you can only reach via a Royal Caribbean cruise ship (shmancy!), the Dragon's Breath Zip Line is a 2,600-foot-long jaw-clencheroo where you go 40-50mph from the top of a tree-covered mountain 500 feet above the beach across a ridiculously massive bay below.
Oh, and not only is this half-mile zip line the world's longest zip line over water, it's also the longest period in the Caribbean. Here's all the cruises that'll get you there. Now go make Tommy Jefferson proud.