This tuna nailed a plastic-tail jig.

Petrels smacked the water all around us, but there was little hint of their quarry. We didn’t see any baitfish skipping across the waves or showering away from predators below. We did spot a few boils under the birds, however, and suspected fish and birds were feasting on something smaller than your typical trolling bait.

The identity of the fishy foragers in question? Little doubt some member of the tuna clan. We hoped it was blackfins, which often feed on tiny baitfish at the surface. If this were the case, we were ready with some appropriately small trolling rigs. Match the hatch, as the saying goes.

A singing drag confirmed our wise choice of lures. A black plastic sand eel had been gobbled by something with muscle.

I’d saddled Capt. Teddy D’Esposito and mate Travis Butters of the Islamorada charterboat Sump’n Special with a tough task. Like many Keys pros, Teddy and Travis are skilled at catching and fishing live bait for blackfin tuna. But, what if they were to limit themselves to artificial lures? In the summertime off-season, no less?

My hosts didn’t flinch at the suggestion.

Frank Herrera, their charter for the day, was so cooperative he stopped at a convenience store to “catch” bait, buying a handful of soda straws the crew would rig for trolling. We also had a selection of other proven lures, including small feathers and plastic eels, which some feel bear passing resemblance to tiny flyingfish.

For weekend fishermen, there are many reasons why you might choose to troll artificials for blackfins and other members of the tuna clan. Bait is sometimes scarce and stopping to find an adequate supply on a bright day may well make you late for the bite. Not all of us throw a cast net well enough to catch lots of bait even if we find it, and catching enough bait with a sabiki rig to also serve as chum can become tiresome at best, or downright annoying if you’re in a hurry. A thousand pilchards in the livewell almost guarantees success but a non-fishing spouse and eager kids might not get the point if you spend hours gathering them.

In the usual rush to get offshore to the Islamorada Hump on a Saturday, Herrera took just minutes to grab some red-and-white soda straws. With a bit more time on your hands, you might come up with myriad colors by visiting a retailer specializing in party goods. The straw rig is a decades-old trick skippers often use when they need a quick pair of bonito for chunks, strips or whole trolled skipping baits. Rigging is easy—just snip a straw into 2- or 21⁄2-inch segments, slip your line through a segment, tie on a medium wire 3/0 hook, and slide the straw over the shank. For the line-shy, small-toothed tunas, there’s no need for a leader. Straight 20-pound-test line is the norm. If the water is a bit rough you might want to slip the line through a 1⁄8- or 1⁄4-ounce egg sinker first. We started with a weighted and unweighted straw.

In case abundant summertime dolphin fry were the food of the day, we also had a couple of rods sporting 21⁄2-inch green-and-yellow squid skirts.

Under our cloud of petrels, a whirring drag soon signaled a hookup. We’d identified the bait of the morning, or so we thought. Our first fish didn’t go far, tied to a 30-pound rig. It was a nice bonito providing little clue to its preferred choice of food. It held an octopus skirt in the right corner of its mouth and a naked hook in the left. While the straw retreated up the line during the fight, the fish had greedily eaten two baits and there was no way to know which one it ate first, though Frank wrestled it to the boat on a squid skirt-rigged rod.

We had a number of mystery bites as we trolled looking for signs of feeding activity. Finally, we found fish headed at us and established a trolling pattern across their path. The fish chased flyers to the surface now and the petrels were wild, flying off in odd directions as bait skipped here and there.

All aboard cheered as one of our eel lures disappeared in a boil and the attached rod bent in an urgent arc. The drag signaled a better fish, too, and we all wondered who might melt first in the heat, angler or fish, as the fight progressed. Frank’s fish wasn’t a blackfin as hoped, but instead a nice skipjack tuna. While no giant, it put up quite a fight on a 20-pound spinner.

Keys seamounts offer the best fishing for tunas much of the year and may offer the only chance at them during the doldrums. You can often find plenty of the blackfins on deeper wrecks, particularly in the melding currents of Key West. Lots of live chum and live baits may offer the best chance for a banner day but it only takes a couple of fish to make a worthwhile day. Trolling lures gives most of us a shot at a great meal and some hot action.