I have a really nice little spot down on the belize border....
www.casadesuenosxcalak.com
You can walk the shore and catch bones, permit, and tons of snapper, grouper and cudas. Take one of my kayaks into the lagoons, baby tarpon, huge snook, jacks, and cudas. Feel like taking a local guide outside the reef or into the bahia Chetumal it is $175 for half day, $250 for full day, and it has been sloooow this year so most of the guides will bargain big time. Had a few buddies take their wives down over Christmas, they fished their asses off, and two of them told me they fell in love with their wives all over again...lends itself really well to a bit of after hours romance!
Tons of Mayan ruins to walk locally, most very untraveled by gringos.
PM me if your interested.....