Definition of flatline
Referring to trolling; to fish a lure or bait behind a boat without adding any weight or directional device to the lure or line. If a diving lure is trolled behind a boat with no weight, diver or other means of altering its depth or direction, an angler is said to be flatlining. If an angler adds an inline weight, dipsy diver or other weight, diver or directional device attached to the line, or runs the line on a planer board, outrigger or downrigger, the angler is not flatlining.
When trolling a number of lines, anglers may fish some lines directionally to the sides of the boat, and some will be flat lined right behind the boat.
When flatlining, the depth the lure or bait will reach is determined solely by the characteristics of the lure itself, especially the size and angle of the bill and the weight of the lure.
Variations of the term flatline
• Flatline trolling
How to use flatline in a sentence
He fished six lures off his boat, two on each side off planer boards, and two flatlined behind the boat.