if you're applying for the US cycle too, start applying to the caribbean schools in december/january (as in submit them then) depending on when you hear back from US schools. the turn around time on the apps is substantially faster (especially SGU) as they are reviewed as they come in and dealt with individually rather than as one big group. If you apply, don't forget that they are also trying to fill January (Ross, SGU) and May (Ross) start date classes as well. I applied at the end of February and heard back from SGU in 10 weeks (so beginning of May) with the results of my interview (which i heard back about 3 weeks after applying). Ross took a bit longer (I had my interview scheduled for 8 weeks after I applied-had to move it back because they chose the same date as SGU and I had already scheduled that one!) so I hadn't even interviewed when I heard back from SGU (which was fine because SGU was my top pick anyway!)
the main reason to wait is because once you hear about an acceptance (which is hopefully what you'll get!), you only have 2 weeks to accept/decline and submit a deposit. You might be able to push it back for extenuating circumstances, but if you haven't heard from US schools, you run into a bit of a problem (either lose the seat for the caribbean school if you want to wait, or lose money you spent applying to US schools).
