Often, the best fishing trips are spontaneous. Some, like this recent shark and tarpon trip to Jacksonville, Florida, have made me immediately block out my schedule next year for a repeat. In early August, my college roommate, Zsolt Takacs, who lives in Jacksonville, called and told me to drop everything but my heaviest fly rods.

This high school marine biology teacher, football coach and photographer had four days left to fish before football practice started, and one of Jacksonville’s best bites was on. Shrimp boats were working right off Mayport Inlet, and when that happens a slough of lazy, large predators, including myriad sharks and tarpon, follow the shrimpers to slurp up bycatch from the trawls. We took full advantage of the action in the wake of these seagoing gravy trains.