There is a kind of 'fence' on the market now. It is a wire mesh which is nailed or tacked onto an existing fence, while the bottom part is buried. I am not going to guarantee it's effectiveness as I have seen snakes climb conventional fences, so I don't know whether they can get past the anti-snake portion or not.
Generally, snakes don't like people any more than people like them. The one exception is the harmless rat snake. A guy at FWC told me one day that they tend to like getting into structures. So typically, if you find a snake in a house or building (I had one in a rental one day scaring the cleaners) it will
usually be a rat snake. They're harmless. Catch-and-release. Just make sure to ID them first.
If it has rattles, it's a rattlesnake--those are easy.
Copperheads are not so common near the beach--they tend to hang out more inland.
Moccasins are usually dark grey or black with markings that are not particularly pronounced...and fairly thick bodies with triangular heads.
Black snakes (which are common here) have no markings and narrow, slender bodies & heads.
Rat snakes look like this...