New to this forum but I will delve into my Belize experiences. I have fished down there for the past 7 years for primarily permit. For the first 5 years, I fished for 7-10 days in April or May, and had success on each trip. One thing I noticed though is that this correlated to the peak season and while the flats were not over crowded you were often not alone. Last year I decided to fish for 8 days with Lincoln Westby in January. He was upfront on the weather and let me know that I could loose a day or two to weather. It was a gamble I was willing to take in return for some solitude. They day I arrived was overcast and rainy as a strong front approached and the next day was less than desirable weather wise; however, we were able to sneak in a quick fish in between squalls and bring a permit to the boat. The next 6 days the weather was perfect and we experienced numerous shots everyday with 3 more permit landed for a total of 4 for the 8day trip.
Based on this experience, I am heading back again in January in 2014. For me, I am willing to take the gamble of bad weather in return for the possible reward of fish that have seen relatively little pressure over the past several months.
A couple of things to keep in mind with Belize. If tarpon are your primary target then look at May into the summer when the migratory fish show up. There are residents that can be found year round but I would plan to fish for other species if outside of the migratory season. The Pelican range that I have fished with Lincoln/Blue Horizon has tons of permit but very few bonefish. Tarpon are around but it depends on whether or not the bait is around...if concentrated the fishing can be lights out for tarpon in the 40-60-lb range. Decide what you want to fish for and then do the research on the desirable areas. For example, the Turneffe Atoll has lots of bones on the Oceanside reefs that run larger than the small runts you often hear Belize associated with. Permit are also plentiful on the Oceanside flats as well as the inner lagoon. You will find tarpon in the cuts there and some large ones at that but it is primarily blind casting with an intermediate or sinking line. This could be a disappointment if you have your heart set on sight fishing the flats for them there. I would be hesitant with fishing around Belize City with the exception maybe being the Belize River for tarpon, and I would not devote a whole trip to that personally. Lots of gill netting in the past and closer to a big population center so it will receive more pressure. Never targeted snook down there so I can't really weigh in on the quality of fishing for them in Belize.