Through the years, there have been many options developed for measuring the amount of line. These range from the actual line being colored differently every 10 yards, to removable in-line counters that attach right to your rod. The multi-colored line concept was simple and inexpensive, but it was easy to loose track of how many colors you actually let out. In-line counters are extremely affordable and accurate, but they can be a hassle in serious trolling situations. Probably the most popular method in recent times has been line-counting reels.

Most of these reels don't really measure the amount of line that is let out. They actually have a mechanism that counts the number of revolutions of the spool. The digits on the display are calibrated to display some increment of feet per number of spool revolutions. When these reels are being designed, the designer has to make an estimate about how much line would be put on the reel. This estimate is the "theoretical spool diameter" that the designer uses when he sets the number of revolutions that occur to make the counter update. Not to get too technical here, but here is the equation that describes how these reels use the number of revolutions to display length of line.

Reading on Reel = (3.14 x (theoretical spool diameter) x (number of spool revolutions)

However, the actual amount of line that the reel is letting out is:
Actual line length = (3.14 x (actual spool diameter) x (number of spool revolutions)

In order to make the reading on the reel match the actual amount of line that is let out, the spool diameter has to be the same as the theoretical spool diameter that was used when the counter mechanism was designed.

The problem is, it can be difficult to get just the right amount of line on the spool so that the counter is accurate. If your "actual diameter" is only 10% different from the "theoretical diameter", you'll have a 10% error in line length. That doesn't seem like much, but consider lures that need to be out 200 feet. With a 10% error, the actual line length will be 20 feet different than what your line counter says. That can be the difference between being in the zone, and being in La La Land.

In order to be effective trollers, and eliminate the potential for errors, I'd like to share a method that I use to get all of my counter reels "dead on". I'll walk you through a calibration session for putting on Fireline with a monofilament backing as an example. When we are done with this calibration, we'll know exactly how much line has to be put on the reel.

I'm going to set this reel up to have 300 feet of 10# Fireline backed by 10# monofilament. I will be using the inexpensive mono backing to calibrate the reel. The only equipment I'll need to do this will be; two counter reels that are the same model and an inexpensive in-line counter.

Here's the process:
1. Tie the Fireline onto reel #1 and hook up the in-line counter.

2. Reel in the Fireline until the in-line counter measures 300 feet.

3. Tie the monofilament onto the end of the fireline.

4. Zero the in-line counter.

5. Reel in the mono until the spool looks like it's a little less than "full", and take note of the reading on the in-line counter.

6. Zero the reel.

7. Reel in more line until the in-line counter says you've added another 50 feet. How many feet does your reel say you've reeled in? If it says you've reeled more than 50 feet, you need to add more line.

8. Repeat steps 6 and 7 until the reel matches the in-line counter. Once the inline counter matches the reel, you've calibrated your reel.

9 Make sure to write down how much monofilament the in-line counter says you've put on. You'll use this number in the future.

10. Tie the end of the mono that's on reel #1 to the spool of reel #2, and transfer all of the line. Now, the mono is on the bottom, and the Fireline is on top...Reel #2 is ready to go.

You will never need to do this calibration again unless you change the reel model, or line diameters. For all subsequent reels, simply tie the mono on first, and set up the in-line counter...Put on as much line as you noted during the calibration process (step 9), and do the same with the Fireline.

Obviously, when you let line out while fishing, the spool diameter will decrease, and your reel will begin to slightly overestimate the amount line that's let out. However, this is not much of a problem in most cases.

Hope this helps, and if you ever see Cabela's Ranger #720 on the water, stop by and say hi.

Note: In Rick's example calibration process, these Cabela's DMG20 reels required 900-ft of 10-pound mono with 300-ft of 10-pound Fireline.

Click here to view line counter trolling reels.

Rick Gardner was born and raised in Colorado where he still resides with his family. A mechanical engineer by trade, he's been an avid angler all his life. He started competitive tournament fishing at the regional level and jumped into the Professional Walleye Trail in 2002. Some of his fishing accomplishments include: Rookie of the Year PWT Western Division, Angler of the Year PWT Western Division, Top Ten PWT Championship Qualifier, Member of the PWT advisory council.

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