This is the broadest family and the one where geography matters least and water matters most. It runs from Baja's desert islands in the Gulf of California, through the Belize barrier reef and the Bay Islands, to the volcanic ranges of the Greater and Lesser Antilles, and out to Galápagos and Fernando de Noronha. What links them is that the sea state, not the rainfall, decides whether a day happens.
The islands split into two kinds of trip that get conflated. Some are mountain trips that happen to be surrounded by water — Pico Duarte at 3,098 m is the highest point in the Caribbean, Dominica's Boiling Lake day is the hardest hike in the Eastern Caribbean, and Cuba's Pico Turquino is a genuine cloud-forest climb. Others are water trips where the walking is incidental. Both are here, and the fitness bars are nothing alike.
This family also carries the heaviest access constraints in the catalog. Galápagos itineraries are assigned to vessels by the park on a fixed rotation, so you choose a boat and its route rather than islands. Fernando de Noronha caps the main island at roughly 11,000 visitors a month with a daily environmental tax and a separate park ticket. Cuba requires authorised-category structuring for US persons. Four of the eight inquire-only expeditions sit in this family, and that is why.