Like many Point Loma-born Portuguese men, Harold Medina followed his father to the sea where he made a living as a tuna fisherman. In the early days, he fished using a pole, then with nets. Eventually — to keep dolphins from being trapped within them — he invented the Medina Panel. The invention is a small mesh required by law on all U.S. tuna boats that keeps porpoises from becoming entangled, allowing them to swim free of the net. Medina, 82, is now retired. But he recently relived his days of glory with captains from the “Deadliest Catch,” Discovery Channel’s docudrama about King crab fishermen’s lives at sea in Alaska. Medina and Capt. Jack Webster, one of San Diego’s working tuna fishermen, took their captain comrades out on San Diego Bay for an episode of “After the Catch,” a spinoff of the series that airs Tuesdays at 9 p.m. through July on the Discovery Channel. Medina, whose uncle and father, Manuel O. Medina and Manuel Machado Medina, helped build the Portuguese Hall on Shelter Island and started the annual Feast of the Holy Spirit – San Diego’s longest running ethnic tradition – remembers first setting out on the ocean blue in 1935 at the age of 8 on his father’s boat. After high school, he returned to the sea to serve with the Merchant Marine in World War II. Along with most of the local tuna fleet, Harold’s father’s boat was procured by the Navy during the war and used to shuttle food, troops and supplies in the South Pacific. Also like many tuna boats, Harold’s father’s boat was lost at sea. When the war ended, the Navy replaced the boat with another, which Manuel Machado Medina converted for pole fishing. “He took me out for one trip when I was 21 and said, ‘OK, it’s yours,’” Harold recalled. “At that time, I was the youngest captain in the fleet.” From that day on until he retired in 1985, Harold Medina skippered four boats: the Alphecca, the Keeri M, the Ocean Pearl and the Zapata Discoverer. “I caught 3,200 ton of fish one year on the Alphecca and 4,500 ton one year on the Zapata – my largest catch ever,” Harold said. Over time, tuna fishing and San Diego’s once-strong fleet succumbed to government regulations, environmental pressure and rising costs. Big corporations closed the canneries on the West Coast, and the industry, once an American birthright, was sold off internationally. Today, the battle still goes on to keep tuna-fishing embargoes in place to protect porpoises that are inadvertently snared during the fishing process. And it’s the American fisherman, not his international colleagues, who, using the Medina Panel, carry on the task of catching fish while saving porpoise. As such, the life of a fisherman has changed since Harold Medina’s days. “Now everyone knows how much they’re going to catch before they go out,” said Capt. Monte Colburn, who helms the Wizard fishing boat and is among the skippers featured in “Deadliest Catch.” “It’s all been calculated out and is regulated.” Today’s fishermen also have technology on board in the form of radar and satellites. In Harold Medina’s days, crews relied on “fish sense.” So does “Deadliest Catch” accurately portray the realities of life at sea? “It’s quite good,” Harold Medina said. “But some of the photos of rough weather all of the time are not real. It’s not every day, all day long like that.” Still, he said, the waters are rough, it is cold and the hazards are real; a dichotomy of an old sea salt’s days trolling for tuna with a pole in the 80-degree waters off Baja California and the Galapagos Islands. These days, Harold Medina, who now lives in Jamul, is a landlubber. He was recently invited to go fishing on a friend’s yacht and couldn’t catch “one lousy fish,” he said. “So I went back and ate sardines – which was the bait.”