LongLiner™ Depth Control
Trolling with your baits or lures just above (or right through) stratified fish is often key to increasing your catch rate. Aggressively feeding fish can go anywhere, but generally speaking, the catching is best when the bait or lure is kept in or slightly above the fish. When fish are stratified, being able to consistently (repeatably) put your bait or lure at their depth is very important. Following is the explanation of LongLiner depth control.
Depth control is an approximation with any method of trolling. The depth of your bait or lure is a function of water density, water current or boat speed, fishing line diameter, the hydrodynamics of the lure or bait, and the length of line between the water surface and the lure or weight. Even with a downrigger set precisely at, say, 30 ft. of depth, a fly on your leader behind the downrigger will be at 30 ft., a spoon at perhaps 31 ft., a flatfish at about 34 ft., and a deep diving plug at perhaps 40 ft. The length of your line between the downrigger and the lure or bait allows different lures and baits to go to different depths, depending on their bouyancy or diving characteristics. Absolute depth of your bait or lure, therefore, is usually not precisely knowable, but highly repeatable depth is easy to maintain with a given lure or bait.
Fishing with a LongLiner gives the angler a compact, easy-to-use means of controlling depth and presentation. Repeatable depth control can be accomplished quite easily at any trolling speed by simply changing the weights attached to the LongLiner to attain a specific line angle; because line angle and line length control depth. (The line angle is the acute angle between the surface of the water and the fishing line.)
A simple way to control your bait or lure depth is to troll your LongLiner with a weight that gives you a 30-degree line angle. You can see from the chart below that for every 2 feet of line below the water surface you will gain 1 foot in depth. One "pull" of 2 feet gives you one foot of depth. You can store this simple formula in your head: "30-degree angle: one pull equals one foot."
Although the 30-degree line angle is the easiest one to remember and use, any weight that maintains a recognized angle will allow you to determine depth regardless of speed, line diameter and length, or water density. Line angle is best determined when your rod is to the side of the boat. After the angle is determined, the rod may be placed directly off of the stern or side of the boat.
Line angle and depth relationships ↓
Line protractor ↓
Length-depth-angle table ↓
