The rafting trip down a three-mile stretch of the Martha Brae is one of the most exhilarating in Jamaica. The journey takes 90 minutes on long bamboo rafts poled by a skilled guide. The upper reaches tumble at a good pace before slowing further down river where you can stop for dips in calm pools. The Martha Brae River rises at Windsor Caves in the Cockpit Country and flows 32 miles to Oyster Bay, east of Falmouth.