Where should I go for a quick trip to Central America?

I am going on a mission trip to Honduras in July and would like to add a 3 day vacation on the end of the trip. Where would be the best place to go and the easiest to get to? I will be flying into San Pedro Sula and could fly from there to somewhere close by or I could stay in Honduras. I definitely want to be close to the Ocean but also don't have a lot of $ to spend. Any ideas, tips, etc. would be greatly appreciated. Thanks!