MARATHON AND TAVERNIER, FLA. — Southport, Conn.-based Summit Development has purchased two marina properties in the Florida Keys from Sun Vest Communities. Summit acquired the Sombrero Resort and Marina — which encompasses 124 condominiums, eight villas and a 54-slip marina — for an undisclosed price. Located at 19 Sombrero Blvd. in Marathon, the property also includes a full-service restaurant, tennis courts and a poolside tiki bar. The company also purchased the 130-slip Mangrove Marina, located at 200 Florida Ave. in Tavernier. Summit plans to renovate both properties. Funding for the purchase was obtained from Orion Bank.