Derek Balmas was all set to go fishing. More precisely, as a first mate for a charter service on the St. Lawrence River, he was all set to take a client fishing. But the client canceled and Balmas suddenly had a day off. He decided to go fishing anyway—a choice he'll likely be glad he made for the rest of his life.
On that early-November day last fall, Balmas climbed aboard Capt. Bob Walters' 31-foot boat that runs out of Clayton, N.Y. Walters is among a handful of seasoned guides on the St. Lawrence River who specifically targets the monster muskies that prowl the waters in and around New York's Thousand Islands Region. With Balmas (who mates for Walters) and another friend...