Founded in 1959, Mariners General Insurance Group in Point Loma writes yacht hull, liability, and marine-business coverage from its Shelter Island office at the center of San Diego's marina basin. Policies extend to marina operators and yacht-club fleets, including the racing and cruising vessels berthed at Southwestern Yacht Club on the same harbor. As an independent brokerage appointed by Travelers and multiple A-rated carriers, the agency shops domestic and international underwriters to match each hull type to the right program. Coverage for charter operators requires passenger-liability endorsements and USCG compliance documentation, a niche the brokerage shares along the Shelter Island corridor with the charter fleet at San Diego Yacht Charters. The most demanding placements involve binding bluewater-cruising policies for owners transiting between U.S. and Mexican territorial waters, layering hull-and-machinery, crew liability, and environmental-spill coverage across multiple jurisdictions.