4-5months central american and jamaica, Route ideas

hi all, im travelling around central america for about 5months i fly into gautemala and fly out of mexico city to jamaica, i need some route ideas, i was hoping to get down to panama and hoping to catch some whale shark diving, i arrive on the 15th march, and in jamaica i can only fly in to montegro bay or kingston, jusking looking for a cool place to chill for a week or so. im on a RTW ticket so i can change dates when needed
thanks all