If in Guatemala, Captain Hook, with Ron Hamlin. My buddy has fished with him several times and highly recommends him. Nice guy, I met him at the Miami Boat Show. He needs pens to write with.
I guess he has a hard time getting them down there. I have fished Costa Rica a few years ago out of Los Suenos on a private boat. We fished there and went down to Golfito. Both were outstanding with Sailfish, Yellowfin, and Wahoo. Unfortunately, I don't know any charter boats to recommend.