Downrigger fishing is a method almost exclusively associated with trolling at depth. In depths of water from 1 - 200 metres a separate braided stainless steel wire line and weight take your bait or lure to your desired depth. When a fish hits your bait, your line is released and you fight the fish on your rod and reel, with no heavy line or weight to battle. Downrigging while trolling is without doubt the most accurate way of presenting a lure or bait at depth, but there is no reason why this technique can't be employed for other fishing methods.
One of my favourite methods of light saltwater fishing is chasing snapper on bait. The traditional method of anchoring and either drifting bait or using heavy sinkers in a strong current can be very effective. We've all experienced the frustration of having small fish (flathead etc) or sea lice play havoc with our bait before a snapper can come close to having a go! In addition, the hassle of having to fight a heavy sinker in strong current takes a bit of the pleasure of fighting a good fish on light tackle. To overcome these obstacles I use my downriggers to present a bait exactly where I want it! I certainly can't lay claim to having been the first to employ this technique, but I've used it for years with great success. I'll try to explain the technique used for this method as well as an explanation of the tackle that I use to catch fish!
Tackle - Rods and Reels
Your choice of rod and reel for this technique are important for consistent success. Whether trolling or at anchor downrigging with bait, my personal preference is for overhead reels. Most of the major brands such as Daiwa, Shimano, Penn, Abu Garcia, etc all make reels that will fill the role admirably. I have used an Abu 7000 for snapper fishing for years with excellent results. Brand loyalty aside, look for a reel with adequate line capacity (300m of 5-6kg line) a dependable star or lever drag and line out alarm or bait clicker. The use of the bait clicker becomes critical when you lower your bait and downrigger weight to the desired depth. I'll explain this further when we talk about rigging and setting lines.
If your personal choice is for spinning reels, look for a reel with good line capacity and a bait runner system. If I were looking for a new reel I would give the new TICA and Okuma bait runner reels a very close look!
Rods for downrigger fishing have some specific requirements, whether used for trolling or bait fishing. Look for a rod in the 7" to 8" (2.1 to 2.4m) with a good parabolic bend. In other words you want a rod that loads from the tip to the butt in a smooth even curve like the letter C. Fast action tippy rods are great for casting or spinning, but they don't really suit this application. A softer slow action rod will allow a better hook set when a fish strikes and releases your line from the downrigger release clip. I prefer rods that handle lines in the 4 to 10kg (10 - 20lbs) range. My favourite rod for this application is a G. Loomis PR845C in GL2. This rod is soft enough to really load up on the downrigger, but is still capable of handling big fish. Rated for 10 - 20lb line the GL2 version of this rod is far more affordable than many other hi-tech graphite rods.
Too often the selection of fishing line receives little or no consideration when setting up for targeting a specific species. By the time the big purchases like rods and reels have been sourced our budget is usually shot. With line our only real connection to a fish, I would suggest it deserves far more serious consideration. When you look for quality line consider the type of fishing you'll be doing. Lines for casting have very different requirements than lines to be used trolling or bait fishing. Descriptions like limp, low memory and great castability are fine for lines to be used for casting, but are not the lines to choose for trolling or bait fishing should be tough, abrasion resistant, with low stretch. I generally use line from 10 - 15lbs (4.0 - 6.0kg) breaking strain for snapper and similar species. You'll find that you can use much lighter line when you don't have to drag a heavy sinker around to get down to the fish, and increase the fun of landing a fish.
The downrigger release clip you use is a vital part of making the whole downrigger system work. I have used just about every style of downrigger release clip over the past thirty years and have settled on a couple of personal favourites. For saltwater applications I prefer the Scotty Hairtrigger and Snapper release clips. The Hairtrigger release clip holds the fishing line in a tapered pin and socket, a screw type adjustment helps regulate the amount of tension need to pop the release. The Snapper release clamps and holds the line between two pads and regulates tension by how far you place the line into the jaws or pads. There are a variety of release clips on the market including Cannon, Magnum and Danica which are also of the pinch pad style. The key to all release clips is how much line tension it takes to pop the release clip. A fairly stiff clip is required to set the hook in a large snapper, though a trout fisherman may want a much lighter release to accommodate smaller fish. Keeping a close eye on the action of your rod tip will keep you informed as to what is happening with your bait. One tell tale sign of a small fish that has hooked up and failed to pop the release clip, is a sudden bouncing of your rod tip. This may be as subtle as a small dipping of the tip to a violent shake, without popping the clip. The following drawing depicts some of the different styles of release clips.
Rigging and Set Up
Your choice of bait for this technique can be whatever you choose. If you have experienced success with pilchards, squid or octopus, stick with it! Whatever bait you choose, make sure it will withstand the rigours of being constantly on the move in the current. The use of berley can have a big impact with this technique, as with almost any form of bait fishing. I have also had good success with attaching a berley cage to my downrigger bomb. To use this approach you will need to stack your bait above the bomb.
The speed of current your anchored in and the weight of your downrigger bomb will also have an impact on your actual depth. Current and the resultant pressure against your downrigger weight will cause the weight to push back and ride higher in the water than what your line counter will read. This phenomenon is known as blow back and can be observed when you watch the angle at which your downrigger cable enters the water. If the cable is running at 90º to the water surface your weight is adequate, if the angle becomes much steeper than you will need to got to a heavier bomb. The deeper you have the weight and the greater the current, the more weight you will need. In most saltwater applications 3.5 - 5.0kg weights will do the job. Downrigger weights come in a variety of shapes and sizes, from cannonball shape to fish profiles. Shape for this technique is not critical, though keep in mind that if you use a round ball shape you will need to stack your release clip above the bomb, as any spinning of the bomb can create nightmare like tangles in your line.
Once you have your bait rigged your ready to set your lines. If you have used your fish finder or depth sounder to locate fish and have anchored securely, your ready to get a line in the water. Lets assume your anchored in 20 meters of water. To set up, your first step is to establish the dropback. Dropback is the distance from your bait to the release clip. As a general rule of thumb the deeper your fishing the less dropback you will need. This should be thought of as a guide, not a cast iron rule. This is the time when a reel with a line out alarm or in the case of a spinning reef, a bait runner, will allow you to feed line out smoothly without fear of a backlash or tangle. Once you have established your dropback, clip your line into the release clip, put your rod in the rod holder and lower the downrigger weight and the rig into the water. The use of a baitrunner or line out alarm will allow you to freespool the reel to let line out without fear of tangles or backlash. Once you have achieved your desired depth, put enough tension on the line to load the rod. Water pressure against your line will cause the line to belly between the rod tip and where your line is fixed in the release clip. Loading the rod in this manner will help pull any belly from the line when a fish hits and the line releases, resulting in a better hookset. I generally aim to have my bait 1.0 - 2.5 meters off the bottom. Sounders like the new generation Lowrance LCX-15 will show you exactly where your bomb is in relation to the bottom, as well as any fish! This is a far more accurate way of determining depth rather than relying on a line counter on the downrigger, which shows the amount of cable out, not necessarily an accurate depth.
Landing a fish hooked on this technique will involve a few on the spot decisions. If your fishing with more than two lines you will have to decide if your going to clear the other lines or continue to play the fish without changing your set ups. There is no easy answer to this question, much will depend on the size of the fish and your personal experience. The size of boat and how many downriggers you have out should also be a consideration. It may be possible to clear lines from one side of the boat and not remove everything. I would personally prefer not to clear any lines until I have to.
Although downrigging has been a popular pursuit in North America for over thirty years it has been used primarily as a trolling tool for targeting freshwater species and Salmon in the Pacific Northwest, from California to Alaska. Applying this technique to other styles of fishing still requires a lot of experimentation and trialing, not to mention the exchange of information that will ultimately benefit the larger angling community. The potential for using downriggers for a host of saltwater sport fish is almost limitless. Charter boats from Hawaii to Bermagui are using downriggers to target Marlin and billfish. If you come up with a technique that works for you, share it around, it will benefit us all!