Best Lakefront or Coastal Places To Visit With Small Children?

Looking for recommendations on places to visit with a 2 year old. Usually we go to Myrtle Beach but we want to try something different. Looking for either a Lake area or another Coastal city/town that is family friendly, affordable, has some quiet water time but also is close to attractions. US ONLY-PLEASE DO NOT SAY ORLANDO!!! Also, can you recommend hotels/b & b's/cabins etc..in that area? THANKS!