This information has been taken from Doug Warren's item in "Up North Outdoors." www.up-north.com/fishstories/dougwarren/whackin.html
Pike are a close range attack fish and require adequate cover to ambush their prey. Casting or trolling near weed edges can produce good catches. Pike lie in wait for their prey along defined weedlines. Try to fish submerged weedlines or exposed weed edge lines in lakes and rivers. The most effective way of covering such areas is by trolling.
The closer you troll to weedlines, the more important it is to keep motor noise down. The louder the engine noise, the farther your crankbaits should be from the boat. With a noisier gas motor, run crankbaits 80 to 100 feet out.
Pike don't hesitate taking a big meal. Large lures, crank baits and plugs up to seven inches long can be used. Line stretch trolling such large lures far from the boat, distance form the edge of the weedline, the trolling depth, and speed of the boat are aspects to consider when fishing pike in this manner.
In many northern Canadian lakes the shoreline is very rocky with quick, steep drop offs. These type of shorelines can be trolled with deep running lures such as the Canadian Wriggler. Experience has proven that trolling close to such deep drop off type of shore lines will produce good catches. When trolling shorelines that are as deep as twenty feet, we often run our lures at the ten foot depth. Depending on the type of lure, the length of line out from the boat is important in order to get to that depth.
An important fact to remember however, is that even though pike may be deeper, pike see upwards very well. Pike will see the lures above them and can be triggered to attack upwards by the glitter and action of the lure. That's why regular lures and spoons that run shallower when trolling, often can be as effective as deeper running baits in such structure.