Yeah, I live in Baltimore, and my wife and I go with our toddler to a beach at a state park. It's a 30 minute drive away, little patch of sand on the banks of the Back River, no waves, not more than 4 feet deep at the deepest part of the swimming area. Lots of shaded picnic tables and we bring food from home. More than one playground if the little guy wants a change of pace from the water. Honestly perfect for us, since shallow, placid river water is a lot more fun for a toddler than straight-up ocean breakers, and big shade trees within a hundred feet saves us schlepping a shade structure.
It's 18 bucks plus gas for a full- to half-day outing.
We bring friends and they're always amazed that it was right under their noses - people in Maryland are just stuck on sitting in traffic for hours and paying for lodging to go to one of the big ocean beach destinations (e.g. Ocean City).