I don't have direct experience with their voice coverage, but I do use a satellite messenger (SPOT X) on Globalstar and have the Garmin inReach on Iridium. The Globalstar network is more limited. It's worked fine for when and where I have needed it (including the western Caribbean), but look at the coverage maps for Globalstar before you decide, and note the SPOT coverage differs dramatically from the voice coverage on Globalstar, particularly in Africa and Asia: https://www.globalstar.com/en-us/coverage-maps. Also, it appears much of the Caribbean is covered, but not all.