Almost since the day salmon were introduced into the Great Lakes, downriggers have dominated the open water fishing scene. The ultimate in depth control fishing, downriggers continue to be a major player when it comes to targeting trout, salmon and even walleye.
Downriggers are without question the foundation of open water trolling, but in recent years a significant number of Great Lakes anglers have begun to focus less on these trolling icons. Riggers are standard equipment on just about every serious trolling boat in the Great Lakes fleet and this realization isn't about to change anytime soon. Still, it's important to note that downriggers are accounting for fewer, not more fish these days.
The big buzz in downriggers isn't about using these depth control aids more, but rather using them less! "I rarely fish more than three riggers no matter where I'm fishing or for what species," says Captain Jerry Lee a 30 year veteran of Great Lakes trolling and one of the more talented multi-species anglers in the fleet. "I've found that the more downrigger lines I run, the fewer fish I tend to catch. Instead of running four or five riggers like I used to do, I now run an out down on each side of the boat, one rigger down the chute and fill in the rest of my trolling spread with a combination of diving planers, lead core and planer board lines."
Less dependence on downriggers is becoming a way of life for charter captains and others who routinely fish the open waters of the Great Lakes. "I've noticed two things that explain in part why over doing it with downriggers is a mistake," explains Lee. "First off the water we're fishing is ultra clear much of the time. Trout, salmon and even walleye are inherently more spooky and tougher to approach in clear water."
"Early and late in the day it's still pretty easy to catch fish using downriggers," Lee goes on to explain. "However, outside these peak feeding periods, it's becoming increasingly more difficult to catch fish on riggers. Too much hardware (downrigger cables/balls, etc.) in the water seems to reduce, not increase the number of strikes."
The clear water and spooky fish are part of the problem, but this isn't the only reason riggers have become less critical to open water fishing success. "I'm seeing more and more fish taken closer to the surface and outside of what would be considered the ideal temperature ranges," explains Lee. "We've discovered that adult salmon and trout often feed in water from 56 to 62 degrees. This is largely because the types of forage available in the Great Lakes has changed over the years."
"Not that long ago chubs and smelt that favor colder water were important forage species," explains Lee. "These days salmon are feeding primarily on alewives that tolerate warmer water."
Lee also points out that fishing temperature breaks or thermoclines to religiously is risky business. "When masses of cold and warm water collide subsurface currents are formed," says Lee. "Often we discover that the colder or preferred temperature water is moving too fast or too slow to provide the desired action from our lures. It's often necessary to fish just above the colder water to get the lure action required to trigger strikes."
There are lots of ways to target open water salmon, trout and walleye, but it's safe to say that diving planers are picking up much of the slack. Once viewed as a supplement to a full complement of downriggers, diving planers have become a mainstream force in open water fishing. Those who fish these trolling aids frequently are responding by finding more effective and creative ways to trout, salmon and walleye. The more you learn about these unique fishing tools, the easier it is to understand why there are more ‘divers down' than ever before.
UNDERSTANDING DIVERS
The many brands and types of diving planers are collectively called "divers" by those who use them most. All of these trolling devices are designed to deploy various lures at depth, but the similarities between brands, models and how each functions ends quickly.
Some divers float, some sink, some are directional and others only dive straight down. Most divers are round in shape, but a few other shapes have emerged and stood the test of time. Some of the most popular models incorporate trip mechanisms that make them easier to retrieve and other do not. Some divers are small and achieve modest depths while larger divers reach depths that rival that of downriggers. Certain models accept rings that enlarge the diameter of the diver and others do not accept after market rings.
Depending on the port you're fishing in or the target species, divers are routinely fished on monofilament, super braid lines or even wire lines. The one thing that all divers have in common is their ability to dive to substantial depths. Ironically this is the single variable associated with divers that anglers and the manufacturers who build these devices know the least about.
BUMPING BOTTOM TO DETERMINE DEPTH
Most of the depth data being shared among diver fishermen has come about through a rather crude means of testing running depth. Letting out line until the diver hits the bottom and noting the lead length and depth on the sonar at this point is how charter captains and other anglers routinely estimate diver depth.
Although this method of determining diving depth is common, it is an inherently unreliable means of measuring the diving depth of trolling lures and hardware. First off, bottom depth is rarely consistent enough to generate accurate and useful data. Even modest changes in bottom depth impact on the respective findings, making it difficult at best to draw any meaningful conclusions from this information.
Secondly, using sonar to determine these depths can be misleading since the transducer for most boats is mounted 18-24 inches below the surface. For this reason sonar units underestimates the actual depth. Unless this underestimate of depth measure is taken into consideration, using sonar to help determine running depths can lead to as much as a two foot margin of error.
Thirdly, just because a diving planer or other trolling device contacts bottom, doesn't mean it has reached it maximum achievable depth. The question is, had the diver not contacted bottom would it have dived deeper on that particular lead length?
Trolling speed is another variable that impacts on diver depth. Because most divers sink, trolling speed must be taken into consideration when testing for diving depth.
The only practical way to determine the running depth of divers and other fishing gear is through actual underwater observation.
A MORE SCIENTIFIC APPROACH
Running things into the bottom to determine how deep they dive amounts to educated guessing. The depth data revealed may be useful from the standpoint of providing some reference, but to say this method provides accurate, reliable and reproducible depth data is simply not true.
The Precision Angling staff recently set out to study diving planers with the help of sophisticated open water scuba gear. Our goal was to determine how variables including line diameter, line type, lead length, trolling speed, diving rings, wave action and the directional settings influence the running depths of these products.
Researching diving planers is a natural extension of the work we've done to determine crankbait running depth since 1991. Our methods for testing crankbaits are straight forward and have been well documented. We troll various crankbaits and other hardware past a scuba diver positioned near a vertical tape measure. We begin by testing short lead lengths. As the lure passes the diver he notes the depth. Progressively longer lead lengths are tested and more depth data collected until the achievable diving depth begins to taper off.
The numerous raw data points collected under water are invaluable fishing information, but to make them easy to understand we plot each data point onto a standard XY graph. The vertical axis shows the feet down a lure or other device is running and the horizontal axis shows the feet back it must be set to achieve specific depths. Because each data point represents a specific depth at a specific lead length, we can literally draw a line that represents the depth a lure will achieve at any lead length.
We call this line a "Dive Curve". At a glance the "Dive Curve" shows how many feet back a lure must be trolled in order to target specific feet down depths. Target depths can be secured by simply manipulating the lead length used when trolling.
The depth diving data just described for popular crankbaits was first published in 1991 in the book Precision Trolling, currently available as the Pro Edition. To date we've documented the diving depth of over 400 crankbaits.
Based on our experience testing crankbaits, we knew it would be also possible to test and confirm the diving depths of other open water trolling gear. In the summer of 2003 we began testing diving planers, lead core line and snap weights. By the end of the summer of 2004 we had observed and documented enough depth diving data to produce a new book called Precision Trolling Big Water Edition, released in November 2004.
Like Precision Trolling, this new depth guide answers the ever popular question "how deep does that dive". However, instead of focusing on crankbaits, this new depth guide zeroes in on the depths achievable with diving planers, lead core line and snap weights. The "Dive Curve" charts made popular in Precision Trolling are used in the Big Water Edition to illustrate at a glance the running depth of popular trolling gear at all common lead lengths and on several popular line sizes and types.
Depth diving data for all the common diving planers including Dipsy Divers, Slide-Divers, Deeper Divers Jet Divers, Deep Six Divers and Mini-Disks are included. Divers that feature after market rings are tested both with and without the dive ring. Each product is tested on not one, but several line sizes and types. Larger divers are tested on 30# test monofilament, super braid and braided wire lines, while smaller divers were tested on 10# monofilament and 10/4 Fireline.
A "Dive Curve" is also provided for each setting on directional divers, clearly illustrating how using the directional features increases outward lure coverage, but also reduces respective diving depths.
In addition, we spent a considerable amount of time exploring the depth capabilities of 18, 27 and 36 pound lead core. Each of these lead core lines were tested at all the common lead lengths and two common trolling speeds.
The data collected is provided in a booklet with laminated pages to protect it from the elements. Available at major retail outlets coast to coast, for more information anglers can call Precision Angling direct at 800-353-6958 or log onto the web page www.precisionangling.com.
FACTORS THAT INFLUENCE DIVER DEPTH
A number of factors influence the depth that divers will run. Some of these variables are obvious and others not so obvious. Variables we examined as part of our research included line diameter and line type, lead length, trolling speed, floating vs sinking style divers, rod position in relationship to the water surface, wave size, the influence of dive rings and also the influence the outboard settings on directional divers have on diving depth.
Some of these variables are rather easy to manipulate, control and duplicate while others are more difficult to standardize.
LINE DIAMETER AND LINE TYPE
Line diameter and line type have a profound impact on the running depth of all diver types. Larger diameter lines generate more friction when they pass through the water than thinner lines, effectively limiting the diving ability of all diving planers. Obviously it makes sense to use thin diameter lines to maximize diving depth, but a point of diminishing return must also be considered. Using lines that are too thin increases problems associated with line stretch and also the working load of the line.
Before beginning our testing process, we interviewed dozens of charter captains to determine what line sizes and types were the most popular choices. The most popular line choice used for fishing divers was 30# test monofilament, with 30# test super braid lines a close second. A significant number of captains also used 30# test braided wire when fishing divers.
The differences in diameter of these three common fishing lines is significant and as you might expect so is the running depth of divers fished on these lines. Interestingly, wire line generated only slightly deeper running depths than super braid lines. Only at extreme lead lengths did wire significantly out distance the diving depth of divers fished on similar diameter super braid lines. Considering the cost of braided wire line and the considerable hassles associated with fishing wire, our testing suggests that super braids are the obvious choice for most diver fishing situations.
Monofilament remains a strong choice for diver fishing, especially when reaching maximum depths isn't important. Monofilament is affordable, easy to fish and the controlled stretch of these lines makes them forgiving even when matched against the strongest salmon.
The super braid selected for testing was 30# test Power Pro with a posted line diameter of eight pound test. Again, this was the most popular brand of super braid among the captains we interviewed.
LEAD LENGTH
Any good troller knows that the further behind the boat you run your hardware, the deeper it will run. Lead length has a profound impact on diver depth. Like line diameter, lead length is limited in part by a point of diminishing return. Using excessively long lead lengths increases line stretch, reduces hook setting ability and simply allows hooked fish a greater amount of time to struggle and ultimately tear free.
In our testing we refer to lead length as "feet back". While testing various divers we documented the running depths at leads ranging from 25 to 240 feet back in some cases. Most divers reach the majority of their available depth at between 120 and 200 feet back. Fishing divers further back than 200 feet only increases maximum depth slightly, while at the same time significantly increasing the likelihood of loosing hooked fish.
Measuring the amount of feet back is a job best handled by a quality line counter style reel. Unfortunately, different sizes and brands of line counters do not enjoy any standardization when it comes to measuring the vital feet back distance. Most brands of line counter reels feature a mechanical readout that meters feet back based on a gear driven counter. As the spool rotates the counter estimates the amount of line playing off the reel. This method of measuring lead length is relatively accurate so long as the same brand and model of reel is used and all the reels have the same amount of line and same pound test line loaded. Since different brands or even models of reels don't have the same spool capacity, diameter or width, they estimate distance differently.
Line counter reels can be easily "calibrated" to insure the feet back information provided is as accurate as possible. Before testing or fishing our reels are calibrated against a tape measure to insure each reel is reading the same feet back as an actual measured distance.
We calibrate our reels based on a 100 foot lead because this distance is in the middle of the feet back zone outlined in our data and it also represents a typical lead used while fishing.
Begin by measuring out 100 feet on a lawn or other flat surface. Drive a stake at the zero mark and tie the line from your rod to this stake. Reel up any slack line and zero out the counter on your reel. Open the bail and walk away allowing line to play out until you reach the 100 foot mark.
Ideally, the line counter reel should also be reading 100 feet at this point, but this may or may not be the case. To calibrate your reel so it reads feet to feet requires either spooling more line onto the reel or removing some line depending on what the counter reads at a measured distance.
If the counter on your reel underestimates the measured 100 foot distance, you'll need to add more line to your reel. Keep in mind that the larger the spool diameter, the more line that will play off with each revolution. If your reel counter is overestimating the measured 100 foot distance you'll have to remove line from your reel until the numbers on your counter and the measured distance match.
It takes a little time to "calibrate" your reels, but this step insures that every reel will be communicating the same information. That way, when you catch a fish on a particular reel and lead length, you'll be able to exactly duplicate that lead length with another rod and reel.
All the brands and models of popular line counter reels can be calibrated using this technique. To get the most accuracy however, we recommend using reels of the same brand, model and line type.
TROLLING SPEED
Trolling speed has measurable impact on the diving depth of certain divers and little with others. Divers that float at rest and dive when trolled like the popular Luhr Jensen Jet Diver react similar to crankbaits when trolled. Trolling speed plays an insignificant role in the depth of these divers. Jet Divers achieve the most consistent and easily duplicated depths because their running depth is controlled solely by line diameter and lead length.
Divers that sink are another story. Because most diving planers are weighted, trolling speed plays a role in how deep they dive. All trolling devices that sink are somewhat speed dependent. That is to say, speed will in part influence the running depth.
Fortunately, the speed dependence of most sinking divers isn't overly significant. Even with sinking divers a predictable running depth can be determined based on lead length and line diameter so long as trolling speed is consistent.
It's the rather large surface area of the typical weighted diver that makes these devices less speed sensitive than you might expect. Water contacting the planing surface does an excellent job of stabilizing divers at predictable depths across a modest range of speeds. For example, the popular No. 1 Dipsy Diver experiences only about 1-2% more depth at 2 mph than it would if trolled at 3 mph. The data provided in Precision Trolling Big Water Edition was all collected at 2.5 mph.
Our speed tests suggest that a Global Positioning System is the easiest and most accurate way to measure trolling speed at the surface. Spinner wheels (especially those associated with sonar units) tend to underestimate trolling speed in a following sea and overestimate speed when trolling into the waves.
DIVING RINGS AND DIRECTIONAL SETTINGS
Many divers are designed to accept after market rings that snap in place and enlarge the diameter of the diver. Adding a dive ring increases both the maximum depth and planing ability. This should come as no surprise to seasoned trollers.
Directional style divers can also be adjusted to increase or decrease the outward coverage of the diver. This is accomplished by rotating the counter weight left or right of the center (zero setting) or straight down setting. Most directional divers have three outward settings to the left and three to the right. The Slide-Diver features six outward planing settings establishing it as the diver that planes out to the side the furthest.
When the counter weight is set in the center or zero setting the diver will achieve the most depth. When the counter weight is positioned in the furthest outward setting the angle of the diver in the water is changed causing the diver to achieve less depth but a greater amount of outward coverage.
The design of the typical directional diver is simple and effective. It's important to note however that divers are better suited to diving than they are achieving significant outward lure coverage. Even when deployed using the maximum outward settings, divers don't come close to achieving the amount of outward coverage possible with planer boards.
Big divers do a better job of planing than small divers. In fact, the amount of outward coverage possible with small divers doesn't justify the outward settings built into these divers. Since these divers are modest in size, it makes the most sense to set them to the zero setting and use planer boards to achieve the necessary outward coverage.
Larger divers can achieve a fair amount of outward coverage, especially when equipped with dive rings that increase their overall diameter. However, even on divers equipped with dive rings the outward planing ability quickly reaches a point of diminishing return.
Our testing indicates that most divers will achieve the maximum outward planing coverage when fished between 100-150 feet back. When longer lead lengths are used, divers tend to pick up additional depth, but outward planing ability is not increased proportionately.
We also discovered that thinner diameter lines like super braid or braided wire allow all sizes of divers to achieve a little extra outward coverage. Reduced line friction allows divers to plane to the side on normal lead lengths, but again at longer leads maximum depth is increased while outward coverage remains about the same.
Lets talk specifics. The No. 1 Dipsy Diver with the dive ring attached runs approximately 50 feet to the side when set on the No. 3 setting and fished 150 feet back. Because of the difficultly in measuring and duplicating outward planing ability we have attempted to make no exact claims as to how far divers will plane. We are instead more comfortable concentrating on how deep divers will run below the surface when fished on various line sizes, types and lead lengths.
Factors that are beyond control including wave size, subsurface currents and the direction of travel in relationship to waves play a major role in how far to the side a diver is likely to plane. We do know however that larger divers plane to the side better than small divers. Thinner lines increase planing ability and the maximum amount of outward coverage is achieved with between 100 and 150 feet back.
WHAT YOU TROLL MATTERS
The types of terminal tackle fished behind a diver also impact on diving depth. Spoons, stickbaits or spinners have little or no impact on diver depth. However, using flashers or dodgers creates more drag in the water and slightly changes the orientation of the diver in the water. Our testing indicated that using a full sized rotating flasher behind the No. 1 Dipsy reduces the diving depth approximately 10% on all line types. The same is true of full sized dodgers.
HOW ROUGH WATER INFLUENCES ON DIVER FISHING
Our diver testing was conducted primarily on calm seas that made it possible for us to take exceptionally accurate depth readings then duplicate them. However, to examine the impact rough seas have on divers we also spent a considerable amount of time testing in 3-5 foot seas. What we discovered confirmed our suspicions that wave action plays a major role in both the depth and planing performance of diving planers.
Trolling into an oncoming wave is the equivalent of increasing trolling speed. Diving depth is reduced when trolling into the waves. In comparison, trolling downwind is similar to reducing trolling speed and the diving depth is increased. Also, as the boat rises and falls the trailing divers are also lifted in the water column and then allowed to sink. This is most pronounced when trolling into heavy waves because the boat's forward speed tends to fluctuate less when trolling downwind.
Trolling across the grain has a different impact. When trolling in a quartering sea one side of the boat will invariably pull harder than the other. Even though the diver and lead lengths used on each side of the boat may be the same, the divers will be running at different depths because of the differences in water resistance pushing against the face of the diver.
In short, anglers fishing divers in rough water can expect to catch fish, but dialing in precise running depths is more difficult compared to fishing in calm seas.
ROD POSITION
The rod position in relationship to the water surface has a significant impact on diver depth. Fortunately, most anglers prefer to fish divers with the rod parallel to the water surface and the rod tip approximately two feet above the water. This is exactly how we tested all divers.
If the rod tip is positioned higher above the water than two feet the resulting diver depth will be progressively reduced as the rod tip is lifted.
SUMMING IT UP
Compared to crankbaits, divers have several more forces impacting them that ultimately influences diving depth. Line diameter and lead length are the primary variables that influence diving depth, but to a degree trolling speed, after market rings, directional settings, wave conditions and rod position must also be taken into consideration.
When tested on calm water with calibrated line counter reels and a stable trolling speed of 2.5 mph, the consistency and the predictability of diving depths achieved with all the popular divers proved to be astonishing. We're comfortable stating that the accuracy of the data collected for Precision Trolling Big Water Edition is plus or minus one foot! That should be precise enough to get the attention of even the hard core angler and refine the fishing skills of anyone who routinely trolls diving planers.
Downriggers are without question the foundation of open water trolling, but in recent years a significant number of Great Lakes anglers have begun to focus less on these trolling icons. Riggers are standard equipment on just about every serious trolling boat in the Great Lakes fleet and this realization isn't about to change anytime soon. Still, it's important to note that downriggers are accounting for fewer, not more fish these days.
Researching diving planers is a natural extension of the work we've done to determine crankbait running depth since 1991. Our methods for testing crankbaits are straight forward and have been well documented. We troll various crankbaits and other hardware past a scuba diver positioned near a vertical tape measure. We begin by testing short lead lengths. As the lure passes the diver he notes the depth. Progressively longer lead lengths are tested and more depth data collected until the achievable diving depth begins to taper off.
In our testing we refer to lead length as "feet back". While testing various divers we documented the running depths at leads ranging from 25 to 240 feet back in some cases. Most divers reach the majority of their available depth at between 120 and 200 feet back. Fishing divers further back than 200 feet only increases maximum depth slightly, while at the same time significantly increasing the likelihood of loosing hooked fish.
Trolling into an oncoming wave is the equivalent of increasing trolling speed. Diving depth is reduced when trolling into the waves. In comparison, trolling downwind is similar to reducing trolling speed and the diving depth is increased. Also, as the boat rises and falls the trailing divers are also lifted in the water column and then allowed to sink. This is most pronounced when trolling into heavy waves because the boat's forward speed tends to fluctuate less when trolling downwind.
