• Dual board planer systems require towing masts, like the two shown here.evening troll image by jimagez from Fotolia.com
  
  A planer board is a flat, floating section of material some fishermen use while trolling--a fishing technique in which a baited line drags behind a slow-moving boat. Planer boards serve as line-separators, and allow fishermen to troll multiple lines without worrying about tangles. In addition, they direct the lines out and away from the boat and its propeller trail (which can scare away fish) and allow you to fish in shallow water without having to take your boat there. There are several different planer board fishing methods you can use, all with their own specific advantages.
  
  

Dual-Board Planer Systems

• Dual-board planer systems feature a set of boards with ski-like runners underneath, positioned across from each other in a parallel configuration (like the twin hulls on a catamaran). According to Captain Steve Lemieux of Mickey Finn Fishing Charters in Maine, fishermen use tow lines attached to masts (typically 6 feet tall) to drag the dual-board planers behind their boats. These masts usually have reels on them, so they can pull the planers in and let them out again. According to LakeErieWalleye.com, the advantages of dual board planer systems over in-line systems include being more resilient in rough, choppy waters and having convenient release mechanisms, known as planer boarder releases.
  
  

Using Planer Board Releases

• Planer board releases have two basic functions. They hold the fishing lines taut while you troll, and they allow you to release a line from the planer board system once you hook a fish. This means you can reel in each rod independently, without having to pull in the toe line and planer as well. According to Walleye.com, you should use a high-tension release clip when trolling for larger fish, like salmon and trout, and a low-tension clip for smaller fish, like walleye. While you can buy release clips of all different tensions at most boating or marine specialty stores, you can also make your own low-tension clip by attaching a shower curtain ring to the end of a plastic clothespin. According to New England Sportsman, to set up a line with your release, you will need to loop some line around your finger and then clamp the clothespin on the loop. Next, snap open your curtain ring and fasten it around the planer board tow line. As you let out line, the clothespin will guide your clip down toward the planer board.
  
  

In-line Planer Boards

• In-line planer boards are typically smaller and less expensive than their dual board counterparts. According to LakeErieWalleye.com, in-line boards attach directly to fishing lines and---in addition to guiding lines outside the boat's wake---serve as fish hit or hook-up indicators (just like bobbers). While some in-line planer boards require that you reel them in each time, others have mechanisms that allow the planer boards to slacken from the line when you have a hook-up (so you can center all of your reeling power on the fish, and not waste any on pulling in the board).