ST. PETERSBURGWhen the Genghis Khan of offshore fishing calls to give you a tip on a great grouper sandwich, you listen. I know I do. Probably whole generations of grouper lose scales when Tampa Bay Times outdoor writer Terry Tomalin's name is mentioned. He knows his good-eating fish.So when he sent me to the Tavern at Bayboro, a fixture on the University South Florida St. Petersburg campus since 1981, I went. The Tavern is known for its selection of beers on tap, daily soups and inviting picnic tables on a covered patio, but has made some changes lately.The "Tav" put in a more substantial kitchen six months ago and owner Tom Herzhauser decided the time was ripe for menu changes. With friends at Fish Busters in Madeira Beach and Nachman's Native Seafood in Redington Shores, Herzhauser has good access to Gulf of Mexico grouper. He buys them whole, brings them back to the Tavern and fillets them himself, then serves fresh grouper sandwiches on Tuesdays and Thursdays for $9.Students and faculty didn't need the call from Tomalin — they've found the deal on their own. On a recent Thursday the tiny indoor dining room was packed with professors (even some from the College of Marine Science, and those guys have to know their fish). A soft, buttered and toasted housemade bun is the perfect cradle for two rounds of ripe Florida tomato, crisp romaine and then the six-ounce piece of fish. The fish can be treated to a range of preparations, from blackened to the one I chose, crusted with cornflakes and sliced almonds and deep fried. Holy moly, a great piece of white, meaty flesh, crunchy-crusted and moist centered, a ramekin of pickle-tangy tartar sauce a classic, luscious accompaniment. Now that what was once a campus secret is out of the bag, the grouper sandwich may rival the Cuban as a top draw at the Tavern at Bayboro. But it's that spirit of rigorous competition that energizes academic life. Tavern at Bayboro is at 120 Sixth Ave. S, St. Petersburg; (727) 821-1418; tavernatbayboro.com. It is open 11 a.m. to 11 p.m. Monday to Thursday, until 9 p.m. Friday.Laura Reiley can be reached at [email protected] or (727) 892-2293. Follow @lreiley on Twitter. She dines anonymously and unannounced; the Times pays all expenses.