I've had a lot of kayaks over the past 40 years. I was strictly a white water guy, then combined that with surfing kayaking, then purchased two flat water boats; one a sit in, the other a sit on top.
While I very much prefer the sit in type for fun (I still play in the white water and surf), I like the sit on top boat for calm water paddles on the Potomac and all the adjacent tributaries, marshes, etc.
The main reason for that is the heat: It gets hot and humid here in the summer (just like Bluffton will) and inside the boat can get icky. It is also a whole lot easier to splash water to keep cool.
All my stuff is really old so no recommendations