Ferries del Caribe (787/832-4800, www.ferriesdelcaribe.com [1]), which provides transportation between Mayagüez and Santo Domingo, Dominican Republic, on a 12-hour overnight voyage, is primarily a car ferry but sometimes it’s like a cruise ship. On select dates, you can book a cabin and make it a mini-vacation by enjoying the restaurant, lounge, game room, and disco. Catch it from the Mayagüez ferry terminal (787/831-3368, fax 787/831-3345, Mon.–Fri. 8 a.m.–9 p.m.) at 31 Avenida Gonzalez Clemente.
Links:
[1] http://www.ferriesdelcaribe.com