Diving depth is the most important spec on a crankbait for trout, and it's the one most anglers don't think about enough. A crankbait that runs two feet above the fish is invisible to them. A crankbait that runs two feet below them is stuck in the rocks. The right diving depth puts the bait in the strike zone — the narrow band of water where a trout will move to eat. This guide explains how crankbait diving depth works and how to choose the right bait for every trout species and water type.
Crankbait diving depth is determined by three things: the lip length, the lip angle, and the line diameter. A long, shallow-angled lip dives deeper. A short, steep-angled lip dives shallower. The line diameter matters because thicker line has more drag in the water, which lifts the bait and reduces depth. To get the maximum depth from any crankbait, use the thinnest line you can get away with — 6 to 8-pound fluorocarbon is the standard for trout crankbaits. The labeled depth on a crankbait is a best-case scenario; in real fishing, expect 70 to 80 percent of the rated depth.
Brown trout are the species that most rewards a deep-diving crankbait. Browns hold in the deepest water — pools, undercut banks, and log jams — and a crankbait that drags the bottom in six to ten feet of water is the tool for reaching them. A deep-diver that deflects off the bottom and pauses triggers reaction strikes from brown trout that aren't actively feeding. The deflection is the trigger — the bait hitting bottom, stopping, and floating up is what makes a brown eat. Fish a deep crankbait slow, and make sure it's hitting bottom.
Rainbow trout are the species that most rewards a medium-diving crankbait. Rainbows hold in faster, shallower water — riffles, runs, and the heads of pools — where a medium diver that runs three to six feet is the right tool. A medium-diver that ticks the bottom of a run in four feet of water, or that grinds along a rocky riffle in five feet, is the workhorse for rainbows. Fish it with a steady retrieve and occasional pauses to trigger strikes from fish that are actively feeding but won't chase far.
Brook trout and cutthroat trout are usually found in shallower water — small streams, high lakes, and the upper reaches of river systems. A shallow-diving crankbait (0 to 3 feet) is the right tool for these species. A shallow crankbait that runs just under the surface, bumping rocks and deflecting off boulders in a small stream, is one of the most effective brookie and cutthroat baits. In small water, a shallow diver fished across the current on a tight-line swing is a classic presentation.
Tiger trout are aggressive chasers that will eat a crankbait at any depth. Match the depth to where the fish are holding — in stillwater, a medium to deep diver that runs five to ten feet is often the right call. Tigers are often stocked in lakes with baitfish, and a crankbait that imitates a baitfish and runs at the depth of the school is the key. Tigers eat hard and fight hard, so don't be afraid to fish a bigger crankbait for them.
Arctic grayling are surface-oriented and rarely hold deeper than three feet. A shallow-diving crankbait or a surface crankbait is the right tool for grayling. They're not aggressive strikers, so fish the crankbait slow with a steady retrieve and long pauses. A small, shallow crankbait in a natural color fished high in the water column will catch grayling when nothing else will.
The retrieve affects depth for all species. A slow, steady retrieve keeps the bait at its maximum depth. Burning the bait — reeling fast — lifts it up and reduces depth. If you need to get deeper, slow down and make a longer cast. In a river, cast upstream and retrieve with the current to get maximum depth — the current helps the bait dive. Cast across and let the bait swing on a tight line to keep it in the strike zone through the entire drift.
Contact with the bottom is what makes a crankbait effective at any depth for any species. A crankbait swimming in open water catches some fish. A crankbait that deflects off bottom, pauses, and floats up catches far more. The deflection triggers a reaction strike — the trout sees a baitfish that has been stunned by hitting something, and it eats it before the bait can recover. If your crankbait isn't hitting bottom or cover periodically, you're fishing it in the wrong place. Choose a crankbait that runs at the depth where the fish are, and fish it where it can hit something. That's the whole game, regardless of species.