How to Fillet Fish Like a Pro

Most fishermen can carve reasonably flat pieces of meat from bones, but pro captains and guides know tricks that cut time while also paring flesh to the bone for a variety of species. I’ve asked several professional guides and captains from New England to the Bahamas for their filleting tips.

Most pros have at least two fishing knives — one for filleting and one for skinning. A straight blade around seven inches long with just a bit of flex will typically provide the best control of a fillet-knife tip as one navigates through and around skin, flesh and bone. For skinning, on the other hand, long, flexible knives do the job better. Nine inches seems about right.

Expensive isn’t necessarily better, but a cheap knife won’t have a blade that’s both flexible and hard enough to hold its edge. ­Forschner and Dexter Russell were recommended by several pros I interviewed.

Fish that aren't very tall from dorsal to belly — like sea bass and yellowtail and vermilion snapper — can be filleted with just one pass. "I make an angled cut from the top to the belly just past its pectoral fin, then I turn the knife and run it right along the fish's spine," says Capt. Carl Griffin of Reel Deal Charters in Charleston, South Carolina. The blade penetrates both belly and dorsal simultaneously, all the way to the tail, and the fillet comes off in one piece. Lay the fillet skin-side down to cut ribs out, and check the fillet along the spine up near the head for remnant bones.

This works well on small mackerel too. “I’ll run the knife through the whole fish in one pass on fish up to about 20 pounds,” says Capt. Jamie Ralph, a freelance captain in Boynton Beach, Florida. A few pieces of backbone stay in the entire length of the fillet, but Ralph cuts these out along with the blood line — the dark meat surrounding the spine, particularly in mackerel, tuna and dolphin.

Larger fish require a half-dozen knife cuts, always working from the dorsal downward. Griffin starts with an angled cut from the head to belly, then he makes “a long cut from the head all the way down the back, just barely breaking the skin.” In the next pass, Griffin says, “I cut along the bones down to the spine, then I work up and over the spine. You have to hold the top half of the fillet up away from the bone to get a good fillet on the bottom of the fish.” Griffin’s fifth cut goes from backbone down to — but not through — the rib cage. As his knife moves toward the tail, the tip comes through the skin from anus to tail. Griffin then uses a heavy serrated knife to cut through the ribs, working from anus up toward the head.

Instead of cutting through the ribs, many pros cut them out while removing the fillet. “Run your knife along the rib bones,” says Capt. Brian Garris, an inshore guide who also works for Reel Deal Charters. “Just don’t put so much pressure on the knife that you break those bones.” This takes some practice on delicate fish like seatrout, so check the fillet and trim out any missed bones.

Striped bass have a pronounced rib cage. "The knife goes along the ribs easily at first, but it gets hard at the steep angle of the rib cage," says Patrick Wood, a mate for Hindsight Sport Fishing in Cape Cod, Massachusetts. "I'll hold the fish down with the knife blade and then rip the rest of the meat off the ribs."

A ragged fillet might not be noticed at dinnertime, but a bit of skin left on the meat stands out. If skinning is a problem, try these tips.

"Use a long fillet knife with a flexible blade," says Capt. Justin Hubbard, who works at Haddrell's Point Tackle in Charleston, South Carolina. "Bend that knife so the point of the blade and the heel of the blade are running right on the table," he says. "It will lie flat right along the skin."

On fish with thick skin, angle the blade down into the skin just a bit. On fish with thin skin, break the job up. “On mackerel, you have to remove the blood line anyway,” Griffin says, so he cuts each fillet down its length into two lengthwise halves, and then skins each. “It’s a lot easier to skin just half a fillet.”

Most pros take the skin off in one or two smooth strokes, but this takes practice. Until then, skin evenly across the fillet, dorsal to belly, a few inches at a time. With the fillet skin-side down on the table, start at the tail, leaving just a bit of meat at the tip of the tail to hold on to. (If you muck it up, try again from the corner near the head.)

“Get a good hold on the skin,” Garris says. “As you move the knife along, keep following with your fingers up close behind the blade so you’ve always got even pressure between the blade and the skin.” Garris says in doing this, you’re also holding the portion of the fillet you’ve already skinned up out of the way.

Many people cut barely through dolphin skin all the way around the fillet, and then pull the skin off before filleting the fish. A glove or pliers helps. This works for mackerel, tuna and other small-scaled species as well, but pros shy away from this trick.

Pulling the skin off leaves fibers of flesh on the skin and somehow also changes the taste of the fish, according to Capt. Lige Lawrence on the Island Hooker in Fort Lauderdale. He'll pull the skin off small dolphin, but he cuts larger fish from their skin. Lawrence divides his fillets in half or thirds while skinning. "Cut about an eighth of an inch above the skin," Lawrence says. "You can feel it. The knife cut gets tougher when you get close to the skin."

Capt. Brett Wilson of Hindsight Sportfishing.com cuts large tuna down the length of the fish along the lateral line. "As long as it's good and cold," he says, "you can reach in and fillet it — take the meat right off the bone — with your hand." To get tuna that cold, he packs ice in and around gutted fish and then adds seawater to make a brine.

While variations to these tips are numerous, there are a few universal recommendations. Keep knives sharp — there are plenty of tools to help. Go slowly — speed comes only with ­repetition. And probably most ­important, pay attention to pros cleaning fish and don't hesitate to ask questions. Most experts will even guide you through a fillet job — but only with your fish!