Re: selling food out on the water
I live in Rochester, NY and I use to run a small business. First of all as a former business owner, don't do it for money. I want to write a book, why not to start a business.
Anyway we did some minor concessions. Prepackage food w/o preperation requires no certificates from the heatlh department. As some other suggested you will have to get insurance, usually $1 mil for liability. The cost will vary. Also the suggested to become a LCC or a corporation will prevent you from being found liable. If I remember correct PA has no sells tax so you don't have to worry that.
When I started my business at first we had prepackaged snacks, drinks, and candy. None of that required anything from the health department as they were already inspected when we got them. So selling a snickers bars, icecream, soda/pop, and hotpockets were okay for us. Customers would use a microwave.
A couple years after I started my business, we moved to low risk prepared foods. We required to have someone who worked for us to get a L2 SafeServe certificate. This allowed the employee to make sure everything was done correct and safely. Cost about $100 if I remember correctly. We were limited in what we could do. We couldn't do major cooking. But we made cookies, had a fountain machine, made pretzels, popcorn, and other concession stuff (all semi-prepared). No raw meats, I don't recall if we were allowed to do hotdogs or not.
To do more complicated stuff we would have to get a L1.
Starting a business is not an easy thing. If you decide to do it, do it for a couple years tops then sell it!
-Hostage
Edit: Forgot to mention we had a concession place that sold all the stuff we bought, it was higher quality foods, etc.