In 1951 in Puerto Rico in the island's nascent days as a sport fishing destination.  Under the mentorship of Art Wills, Tommy Gifford and Johnny Harms, Benitez learned the finer points of fishing the waters of his home island, as well as the Virgin Islands and the Bahamas. He obtained his captain's license, built his own boat and bought Wills' charter business.

Benitez's contributions to Puerto Rico sport fishing include guiding a client to a 756-pound blue marlin world record in 1956 that put the island on the map. In the 1960s and 70s, he was involved with The International Billfish Tournament at Club Náutico de San Juan; Johnny Harms’ marina in St. Thomas;  the USVI Open/Atlantic Blue Marlin Tournament (known as the “Boy Scout” Tournament); and many more projects. He widened his explorations to  Hawaii, Florida, North Carolina, Louisiana, Brazil, Venezuela, Panama and Australia, where in 1973 he caught a 1,162 pound black marlin with Capt. Peter Wright. In the 1990s he operated a charter boat out of Madeira in the North Atlantic.

Benitez received the IGFA Chester H. Wolfe Outstanding Sportsmanship Award in 2011. That same year, during the first IGFA Great Marlin Race, he implanted a satellite tag in a marlin that surfaced off the Angola coast 120 days later-- 4,776 nautical miles from Puerto Rico. It happened January 5, 2012-- two days after Benitez passed away.