We went to PEI last summer and are planning on going back next year. Like rwbradley wrote: " PEI is like going back in time "....Remember Little house on the Prairie !
We stayed at Cavendish Sunset campground right in the heart of Cavendish. The campground is situated behind the boardwalk and across the street from the beach. They charge a fee at the entrance of the beach, but you will soon find out there are plenty of beaches that are free.
The water is the Gulf of St Lawrence , which is as large as an ocean but the warmest water north of Virginia.
PEI is known for their mussels and the best place we found was the Blue Oyster restaurant in North Rustico.
I forgot to mention....people are super friendly and always ready to help.
Have fun and enjoy......Lucky you !