I'm just assuming the spaniel part of your name is referring to a boykin...if that's the case, I would consider using him once temps have been down/near freezing for a few nights, and not breaking upper 40's, low 50's during the day. That's on the local lakes in water that's deeper than he can stand (other than Talquin and Seminole, I wouldn't put a dog in the water there period.) Ponds, creeks, etc. are entirely up to you.
The coast has more hazards to consider than just oyster bars. Stingrays, shells, and of course...sharks. I've never heard of a dog getting attacked while hunting in this area, but that's not to say it couldn't happen.