Roatán Island in $350s-$510s RT

Off the coast of Honduras, there's a little sliver of Caribbean paradise!

While the mainland is all about rainforests and waterfalls, the island is almost like a fully separate country — laid-back and beachy, with some of the best snorkeling/scuba in the world. You can swim through mangroves with dolphins, dive through a shipwreck, and feast on grilled snapper before the sun even sets. 

And what a sunset it will be!

These dates are rapidly approaching, but if you want something later, take a look at the Google Flights calendar. Each of these routes also has some later dates for $50 RT or less, like these August dates from Tampa, or this fare from Vegas all the way in next January.