Regaining balance after boating?

I went boating over the weekend. It was fun and I didn't notice any problems until I got home. We weren't on the pontoon boat for more than 4 hours in a day. However, I am having trouble regaining my balance. It has been this way for 3 days now and it is really starting to freak me out. I just feel like I am still in the boat. I still have a sense of a rocking motion and I am just wondering if anyone can tell me what is going on, or what I can do about it. I don't know if this has anything to do with it or not, but I also went swimming in a lake. Can anybody out there offer me anything about what it is that has made my equilibrium so messed up?