judy . other than going long haul I think the only places you can guarantee good weather at that time would be Egypt , canary islands , maybe morocco or cape verde which is a newish destination.

Egypt (red sea)would be my choice but if you need life outside of your hotel then maybe the canary islands would suit you better.

lyn

If the lads are competent swimmers and like snorkelling then somewhere like the Conrad in Sharm might be a good choice. The lads in our party spent hours every day just snorkelling about watching the different fish.
If they are very good swimmers then possibly the LTI Grand Azure. The only 2 we have stayed at so can't comment on the others.
With the Conrad, you can walk up the jetty and drop straight into a lifesize tropical fish aquarium, whereas with the LTI you still have another 50m of rock climbing to go after walking along the 800m jetty! On the plus side the facilities at the Grand Azure were slightly better with more pools, water slides, more restaurants etc. Both have comprehensive threads in the Egypt forum.

We also did Mexico last september/october and it was warm over there.
We chose the Grand Bahia Principe Coba as it was next to Xel Ha and not too far from Xcarat. The lads might like both of those places. They have easily found websites, but in a nutshell Xel Ha is an ecological park where the main attraction is floating or snorkelling down the river. There is a jump point halfway down where you can jump 20 ft or so into the river and climb up the steps or up the holes in the cliff.
You cycle to the head of the river and don snorkel equipment, life jacket and flippers and then jump on a rubber ring to head of down the river. Our kids found a giant turtle popped his head up alongside them on the way down. There are plenty of massive fish to interact with -you see a feeding frenzy and just jump in along with them! I even spotted one bird "flying" underwater with the fish. The kids would probably have a great time. There is also the chance to swim and interact with dolphins.
Xcarat is more a theme park but the main attraction is a similar river but this time underground although there is an alternative route which spend more time outside. There is more to see and do but ours did the dolphin experience which we felt occupied too large a chunk of the day so maybe the Xel Ha would have been a better option as we didn't get to half the attractions in Xcarat. The evening show was excellent. Even the kids enjoyed it.