Ship to Marsh Harbour. Marsh Harbour. Dubbed the “Boating Capital of The Bahamas,” The Abaco Islands highlight their popular settlements and Cays as key tourist attractions. With a population of approx. 13,000, the Abaco Islands are the second largest island chain the Bahamas. Their majestic Cays are scattered over 130 square miles of Bahamian water and the capital Marsh Harbour is the commercial center of these islands. SEACOR Island Lines makes regular trips to this port two days a week.