Marinas are areas of water where privately owned boats are kept. They provide utilities and services like berthing, water, electricity, and sewage facilities. There are three main types - ocean class for large full-service marinas, coastal class with fewer amenities, and yacht stations for small marinas along coastlines. Well-designed marinas consider factors like protection, water depth, and surroundings. They can boost tourism through boat visitors who stay longer and spend more. Major international marinas include Port Vell in Barcelona and Marina Grande in Capri. India's first international marina is Kochi Marina, providing berthing and facilities. Navi Mumbai plans to develop marinas and waterfront areas.