Easter Sunday next year is 8th April, and any time before then will be considered "high season". You might want to consider coming a little later, say mid-April, when prices will drop.
I can't make any recommendation for anyone else, but I have boarded flights in San Pedro for Belize City when I've still been dripping from two dives, and I've had no problems. On that occasion I had been diving nitrox, and at my request the plane didn't go above 800ft. The normal cruising altitude is around 1500ft, and I've never heard of anyone having a problem. But it's up to you to decide - my official recommendation is not to fly at all for 12 hours after even a single dive. Diving nitrox really helps, and being well hydrated before and after the dives is important. If you'll be diving and flying on one particular day, stay off the alcohol the previous evening.
The best base for most inland trips is San Ignacio. Attractive and cheap, well located and tourist-orientated.
It may not be useful to you, but there are now direct flights operated by Tropic Air from San Pedro to Belmopan. Relatively expensive but save many hours.
If you want to go to ATM (good choice) I would think twice about also going to Tikal. To "do" Tikal properly takes several days - you want at least two nights near there - and it's also very costly taking all into account. I would think about staying in San Ignacio and "doing" ATM and some of the Belizean Mayan ruins from there. Right next to San Ignacio are Xunantunich and Cahal Pech, with the first being more impressive and the second more historic. An organised day trip can take you to Caracol, one of the most important of the Mayan cities, and a lovely drive through (Belizean) jungle.
I would also want to do at least a third day of diving.
I can't make any recommendation for anyone else, but I have boarded flights in San Pedro for Belize City when I've still been dripping from two dives, and I've had no problems. On that occasion I had been diving nitrox, and at my request the plane didn't go above 800ft. The normal cruising altitude is around 1500ft, and I've never heard of anyone having a problem. But it's up to you to decide - my official recommendation is not to fly at all for 12 hours after even a single dive. Diving nitrox really helps, and being well hydrated before and after the dives is important. If you'll be diving and flying on one particular day, stay off the alcohol the previous evening.
The best base for most inland trips is San Ignacio. Attractive and cheap, well located and tourist-orientated.
It may not be useful to you, but there are now direct flights operated by Tropic Air from San Pedro to Belmopan. Relatively expensive but save many hours.
If you want to go to ATM (good choice) I would think twice about also going to Tikal. To "do" Tikal properly takes several days - you want at least two nights near there - and it's also very costly taking all into account. I would think about staying in San Ignacio and "doing" ATM and some of the Belizean Mayan ruins from there. Right next to San Ignacio are Xunantunich and Cahal Pech, with the first being more impressive and the second more historic. An organised day trip can take you to Caracol, one of the most important of the Mayan cities, and a lovely drive through (Belizean) jungle.
I would also want to do at least a third day of diving.
