The Caribbean's Leeward Islands offer some of the best conditions for sailing, and people flock to the area because the combination of warm sun and steady winds can't be beat. Antigua & Barbuda is a nation with a reputation for fantastic sailing and many (365!) wonderful beaches. Antigua has the requisite deep harbor that boats love for maneuverability, and Antigua's English Harbor offers protected shelter from the elements. So why go to Antigua if you're not a sailor? For the landlubbing, of course!
The northwestern coast of Antigua has a couple noteworthy beaches: Dickenson Bay and Runaway Bay. The beaches are popular and will always keep your group entertained. The good part about being near one of Antigua's centers of activity is the abundance of amenities. Here in this area you will find restaurants, bars, sports, vendors, and street food. All of this- plus public restrooms- means that you will be amused and comfortable all day long.
If you like staying near a main town, then spend a day in the coastal area surrounding St. John's. Both Fort James and Deep Bay offer a relaxing Caribbean beach experience. The land on which Fort James (an actual fort) was built is strategically important. For those of us more concerned with marine life than military plotting, this simply means that Fort James has terrific views of the region! Deep Bay is great for swimming, and the bay has a shipwreck that makes for wonderful snorkeling.