I'm not familiar with that resort but you should be able to snorkel keeping the following in mind. You are required by Florida law to tow a Diver Down Flag behind you. They are sold in many stores down in the Keys attached to a float. And even so you better keep an eye out for boats which may be driven by idiots who have no idea what that flag means and/or may be drunk. You read in the local papers about drunk boat operators getting themselves killed or killing others all the time down here. I doubt if one in ten of boat owners or renters down here have taken the CG Aux safety classes. The Florida Marine Patrol is offering them too in an effort to cut down the number of stupid accidents on the water.
I cannot imagine why kayaking would be a problem. But wouldn't both be easier from the beach near the piers?