Donovan’s Reef isn’t a bar you find, it’s a bar you get directed to by everyone you meet on Martha’s Vineyard. Tucked below Nancy’s Restaurant at the Oak Bluffs Harbor, it’s the outdoor domain of Donovan, a Jamaican bartender who has been blending frozen drinks for island loyalists for decades. The signature is the Dirty Banana (rum, chocolate, banana, cream), and the line for one can stretch an hour on a summer afternoon. Nobody seems to mind. Donovan works the blender like a one-man show, remembers faces and drink orders from years back, and keeps the reggae flowing. It’s the rare beach bar where the bartender is genuinely the attraction.