A trotline for catfish is a long, weighted mainline stretched across a river channel or lake flat, rigged with evenly spaced drop lines and baited hooks, anchored at both ends and checked on a regular schedule. Done correctly, it fishes passively around the clock, covering water column and structure that a single rod cannot, and it consistently produces channel cats, blue cats, and flatheads once the mainline is positioned on a travel route or feeding flat.
Reading the Water Before You Set a Line
Catfish relocate with water temperature, current, and oxygen levels, so the trotline has to go where the fish actually are, not just where it is convenient to tie off. On rivers, target the outside bends where current has scoured a deeper channel, the tailouts below wing dikes, and the seams where fast water meets slack water. Catfish hold in these transition zones to ambush food drifting past without fighting the main current. On lakes, look for creek channels, submerged roadbeds, and the base of dam riprap. Flatheads in particular relate to woody cover and will hold tight to a laydown or brush pile, so a line that clips the edge of structure without snagging in it will produce better than one set in open, featureless water.
Water clarity matters as much as depth. Stained to muddy water lets you set shallower, sometimes just three to six feet down, because catfish rely on smell and vibration rather than sight to locate a bait. In clear reservoirs, push the line deeper, ten to twenty feet, where light penetration is lower and fish feel more comfortable feeding during daylight hours.
Gear You Need
Mainline and Anchors
Use a heavy nylon or braided mainline rated well beyond what any fish on the line could break, typically 130 to 300 pound test depending on the size of catfish in your water. Tarred braided line resists rot and abrasion far better than untreated cord if you plan to leave a line set for more than a day or two. Anchor each end securely, a cinder block, a sash weight, or a stake driven into the bank all work, but the anchor has to hold against current surges and against the thrashing of a large fish hooked mid-line. A line that pulls loose at one end collapses the whole set and can tangle every drop.
Drop Lines and Hooks
Space drop lines three to six feet apart along the mainline using swivels or trotline clips so each drop can spin freely without twisting into its neighbors. Drop length should run twelve to eighteen inches, short enough to keep hooked fish from tangling the mainline, long enough to let bait move naturally in current. Circle hooks in the 5/0 to 8/0 range are the standard choice because they hook fish in the corner of the jaw as the fish turns away, which means far fewer gut-hooked catfish and a much higher percentage of fish still alive and in good shape when you run the line. Quality terminal tackle from a well-stocked all-tackle selection makes the difference between a line that survives a season and one that fails after the first big flathead.
Floats and Weights
A jug float or a marked buoy at each end of the mainline lets you find the line again in low light or stained water, and intermediate floats can be added on long sets to keep the mainline from sagging to the bottom and fouling on debris. Add a small weight near each drop in current-heavy water to keep bait pinned near the strike zone instead of drifting downstream of the hook.
Baiting the Line
Live bluegill, shad, and small carp fished on drop lines will draw flatheads and big blue cats that prefer live prey. Cut bait, particularly cut shad, skipjack, or cut bluegill, works well for channel cats and blues that are keying on scent and oily flesh rather than movement. Stink baits and dip baits pack the most scent per hook and shine in warm, stained water where current is minimal. Some anglers also thread soft plastic grubs or curl-tail baits scented with catfish attractant onto drop hooks as a low-maintenance option that will not spoil or fall off between checks, and a scented soft plastic from the soft-plastics lineup can outlast natural bait on a line left overnight in warm water. Jig heads with built-in weight, sourced from the same jigs category anglers use for casting, also work well as a base for rigging cut bait since the weighted head keeps the bait down without a separate sinker.
Setting the Line
Run the mainline perpendicular to current on rivers so drops swing naturally with the flow, or along a contour line on lakes so every hook sits at a consistent depth. Stretch the line taut between anchors, since a slack mainline sags and lets drops tangle together. Bait each hook just before deployment, working methodically down the line so bait stays fresh and hooks stay sharp. Lower the line into the water gradually rather than dropping it in a pile, which prevents the drops from wrapping around the mainline on the way down.
Cadence: How Often to Check the Line
Check a trotline at least once every twelve to twenty-four hours. Longer intervals risk losing fish to other predators, to drowning if hooked catfish cannot reach the surface, or to bait spoiling and losing its draw. In warm summer water, shorter intervals of eight to twelve hours keep bait fresher and reduce stress on hooked fish. Approach the line slowly by boat, lift the mainline hand over hand, and rebait or reset hooks as you go rather than pulling the entire line before working it. Many states regulate trotline check intervals and require tags or ID markers on each line, so confirm local regulations before you set gear in the water.
Common Mistakes to Avoid
- Setting the mainline too close to the surface in high-traffic waterways, creating a hazard for boat traffic and increasing the odds of the line being cut or stolen.
- Spacing drops too tightly, which causes constant tangling once a fish is hooked and thrashing.
- Using undersized hooks for the target species, resulting in straightened hooks or torn-out bait on larger blues and flatheads.
- Leaving a line unchecked for multiple days, which leads to spoiled bait, dead fish, and wasted effort.
- Ignoring current changes after rain, when a line set in a calm eddy can suddenly be hit with a surge that drags anchors and collapses the set.
Common questions
What is the best hook size for a catfish trotline?
Circle hooks between 5/0 and 8/0 cover most channel cat and blue cat situations. Step up to 8/0 or larger, paired with heavier drop line, when targeting flatheads over ten pounds, since their bony mouths and thrashing power demand a hook with more gap and a stouter shank.
How deep should a trotline be set?
Depth depends on water clarity and season. In muddy river current, three to six feet often puts bait right in the strike zone. In clear lake water, ten to twenty feet along a channel edge or creek bend usually holds more active fish, especially during summer when catfish move deeper to escape heat and bright light.
Is bait or live fish better for a trotline?
Cut bait and stink baits excel for channel cats and produce well with minimal upkeep, while live bluegill or shad tend to draw larger flatheads and blue cats that hunt more by movement than scent. Many experienced trotliners alternate bait types along the same line to cover both feeding styles and see which the fish favor on a given day.
A well-planned trotline rewards preparation more than luck. Study the water, rig with dependable terminal tackle, bait with intent, and check the line on a disciplined schedule, and it will consistently outproduce a single rod sitting on the bank. For more species-specific tactics and rigging breakdowns, browse the full library of all fishing guides.