Offshore Fishing

There is so much I love about offshore fishing. I love the anticipation involved in getting the boat ready, prepping the bait, and the growing anticipation as the crew assembles. I love the freedom offered as the boat pulls away from the dock and the sights and sounds as a new day dawns over an open ocean. Notice I didn’t say anything about catching fish and that is true. If I go wahoo fishing and don’t catch a thing (and it happens to everyone), I still have a great time. However, the reality is that if you continue to go without success you, and your crew will eventually become discouraged. When that happens all kinds of negative thoughts begin to creep into your mind: how much fuel did I just put into the boat, what else could I have done today besides go fishing, and on and on. The next thing you know the boat has been sitting at the dock for a couple of weeks or more.

The purpose of this article is to consider a few things to hopefully make us more successful as we pursue our goal. The focus will be fishing for pelagic species such as wahoo, dolphin, tuna, and billfish, but the principles apply in many other saltwater fishing scenarios. Lastly, the takeaway should be to answer the question of what can I do to increase the odds that my ballyhoo will get in front of the fish I’m after. In broadest terms, I would liken it to playing blackjack in Las Vegas. As I examine the cards in my hand and what I know of the dealer’s hand, what can I do to tilt the odds in my favor? I would always encourage you to never head offshore without a plan.

Saltwater Trolling

The further offshore you are going, the more important the plan becomes. The open ocean is vast and experts say 90% of the fish we are after will occupy about 1% of that water. That sounds a little like looking for a needle in a haystack, but if you are consistently fishing in the right 1%, your odds are significantly improved.  To be successful you need to find the pockets of water where fish are congregating. Fish are relatively simple creatures and care about two major things: 

1. Food source – Bait is arguably the most important factor when determining where fish will congregate. For example, a Mahi will eat between 10%-20% of its body weight daily. If you are yellowfin tuna fishing and find the bait, you will often find the fish. 

2. Living Conditions – Pelagic fish are very particular when it comes to where they will and will not travel. Just like a human will always seek shade on a hot day, pelagic fish tend to prefer specific temperatures, salinity levels, and clarity. Ideal conditions will vary by specific species, but in general you will have the best luck in clear blue water that is between 75 and 85 degrees. 

It helps to think of the areas we fish as two distinct bodies of water: inshore and offshore. The inshore water is characterized as nutrient rich, lower salinity, lower water clarity, green in color, with generally less current. The offshore water will be almost just the opposite: blue, clear, stronger current, less nutrients, and a higher salinity. When looking for fish, it helps to think like a fish. Ask yourself what makes a fish happy? If a fish is comfortable and can find something to eat, that fish is happy. Fishing success is simple, find happy fish! 

Generally baitfish will tend to be in the inshore water. The increased nutrients encourage the growth of phytoplankton (making the water greener) and provide a food source. The conditions offered by the offshore waters tend to make pelagic species more comfortable. Consequently, regions where these two bodies of water converge greatly improve the opportunities to troll your lures in front of that trophy fish. The interface between these two bodies serves as a fence keeping baitfish from venturing further offshore and the gamefish don’t have to travel far out of their comfort zone because they are able to locate food. So how can we consistently find the inshore/offshore interface that helps us begin to concentrate on likely productive water? Pelagic fish are constantly moving in search of food and favorable living conditions. These gamefish are able to cover incredible amounts of ground in a single day. This makes every day on the water a new day. Just because you crushed it dolphin fishing in one area last weekend doesn’t mean you will again next weekend. Sometimes you tell yourself I just have to put some miles down and find where the fish are holding today. This doesn't seem like a reliable way to begin your offshore adventure. As we start formulating a gameplan, begin by considering how characteristics differ between inshore and offshore waters, namely temperature, salinity, chlorophyll, current, and color. Without question, the best way to look for these characteristics is using satellite imagery. For the sake of discussion, I’ll be using RipCharts as the example. I have used several services over the years, but currently use RipCharts. For me, it has some features I find helpful. Any of these services will work. Just find one that works best for you. However, with the cost of fuel, a satellite imagery service is arguably a cost saving service and I don't recommend not using one (even a free service)! We’ll examine each characteristic individually, but remembering the purpose is to identify the interface where inshore and offshore waters meet. Earlier I likened gradients in water characteristics as a fence that tends to congregate fish at the boundary. Keep in mind, the steeper the gradient (the more abrupt the change), the “taller the fence” and the more likely it will concentrate fish.

SST Charts

Temperature- Sea surface temperature (SST) is just that: the water temperature at the water's surface. SST by far gets the most attention when discussing satellite imagery and a sharp 1-2 deg temperature break can definitely concentrate fish. Finding a good temperature break is always a big positive. The challenge is that temperature data is dependent on cloud-free conditions. Imagery can’t "see" through clouds and optimal cloud conditions are often few and far between. To combat this, satellite imagery services use very sophisticated algorithms to compensate for cloud cover, but accuracy will be the sacrifice. Secondly, as the summer heats up, water temperatures can tend to become a lot more homogenous and makes distinguishing that inshore/offshore interface a lot more difficult. Always consider SST, but don’t despair if the information is ambiguous.

Chlorophyll- Chlorophyll is another characteristic easily identified using satellite imagery. The chlorophyll satellite images help to spot where water conditions (primarily nutrients) are such that algae (phytoplankton) can bloom and initiate a whole life cycle of small fish feeding on algae, slightly larger fish feeding on the small fish, and so on up till the big boys move in!  Unfortunately, like temperature images, chlorophyll images are hindered by cloud cover and can often be sketchy at best. There are a couple of things to note on the image shown. First off, I would not necessarily say there was a clear area where the gradient is significantly sharp, but the interface between offshore and inshore water is pretty definitive.  

rutgers sst charts

Secondly, the gray area to the right is an area with cloud cover making chlorophyll data (and SST data) not available.  So we've made some good progress! We considered two characteristics of inshore and offshore waters that are readily discernible usable using satellite imagery and very useful for locating those potentially productive boundary areas. The downside is their usefulness during cloudy conditions. Let's continue and consider other water characteristics that may be useful to consistently find productive offshore water.

Salinity- Salinity is the amount of dissolved salt in the water. Typically inshore waters are influenced by rain and freshwater input from rivers, which results in a lower salinity. Not only does salinity differ between inshore and offshore waters, it can also be useful to differentiate oceanic streams. The interaction between the Gulf Stream and Labrador Current is one example. The salinity satellite image to the right illustrates some of the interesting features often available. It also illustrates the subtlety of salinity differences inshore versus offshore. One particularly attractive feature of salinity satellite images is that they are not dependent on having cloud free conditions. You can always count on having salinity information regardless of the cloud conditions. The



downside, particularly when differentiating inshore from offshore water, is that the gradient is often gradual. This subtle gradient translates into a wider uncertainty of exactly where the inshore/offshore interface exists. 

Current- Current is another characteristic that differentiates coastal inshore waters from offshore water. Again it is easily distinguished using satellite imagery and it is also independent of cloud free conditions. There are also some other advantages afforded by current as it interacts with structure and we’ll consider those in more depth later. For now, let’s just recognize current as a water characteristic, which is independent of cloud conditions and that we can use to differentiate inshore from offshore waters. The takeaway thus far is to utilize a satellite imagery service to examine all the water characteristics you can in order to identify the interface between inshore and offshore water. Gradients in these characteristics tend to congregate fish. The steeper the gradient, the “taller the fence” and the greater the likelihood 

SST fishing chart

that those waters will be productive.  Don’t necessarily consider these characteristics independently, but look for areas of convergence, areas where multiple water characteristics intersect and with the steepest gradients. Remember the idea is to utilize as much information as possible to focus our efforts on what is likely the most productive water and tilt the odds of locating gamefish in our favor.

Structure- Another piece of information available to us before we leave the docks is structure. There are a myriad of sources available to identify structure in your fishing area. Structure is very important if you are mackerel fishing, king mackerel or Spanish Mackerel.  If you have been fishing long, it is likely you have already used these sources to identify those areas of structure. Don't only consider the structure itself, but also its interaction with current as well. Why is structure so important? First and foremost, structure provides cover for baitfish and they tend to congregate around structure for the protection it offers. However, the structure is also a double edged sword for the baitfish in that it also creates current eddies that can disorientate baitfish and push them out of their cover to waiting gamefish.

Wahoo fishing

Structure can come in many forms including: 

● Swells and humps in the ocean floor 

● Rocks 

● Ledges 

● Wrecks 

● As well as the edge of the continental shelf 

In addition to providing cover for baitfish, structure and current can interact and lead to upwellings from deep ocean water that can drive nutrient rich water from the deep up to the surface as the water is forced up and over the structure. This conveyor belt of nutrients initiates a lifecycle of algae bloom attracting baitfish and is famous for congregating pelagic species. At times, the current from the upwelling is so strong it can produce sections of extremely rough water on a day when the surrounding waters are glassy calm. 

A good topographical map can be very useful in this effort. The closer the bottom contour lines on a navigational chart, the more severe the drop-off and, usually, the better the area for attracting bait and gamefish. Additionally, offshore currents can cause eddies of offshore water to push inshore. These eddies are often visible with satellite imagery. Watch for these because often these small pockets of water can be very productive areas. 

Once you’ve focused on the areas of water that make the target species comfortable, consider structure. Ask yourself where is there structure located in the area where favorable water characteristics converge? Don't look for structure first. Many people don't do their homework and they just go to the structure they always go to. Until you break that habit, your fishing results will likely always be inconsistent. Do your homework!  Ultimately, using available information to eliminate a lot of unproductive water does not have to be a complicated task. When broken down, use satellite imagery to look for converging favorable water characteristics. Secondly, consider structure that may exist in those favorable areas to provide even greater focus.

fishing using birds

Visual Cues- At some point though, it comes time to head out and do what we love to do and that is fish! Even though we have done everything possible to identify the most productive water, there is still a lot of water left. At this point, the entire crew needs to use all available visual cues to help further focus your fishing attention. We can be confident conditions are favorable for our quarry to be comfortable and that baitfish can't be far. However without bait, gamefish will probably not be abundant in an area and even if you find some, they won't stay long if baitfish do not come on the scene. Without baitfish, you are usually better off continuing to explore other areas with favorable conditions rather than trying to wait out the arrival of fish.

Somebody told me one time that sailfish fishing is a "contact sport", you have to keep moving till you make contact!  This is not only true for sailfish.  Seeing baitfish is obviously the best visual cue that bait is in the area. Seeing baitfish might be seeing them on a chart recorder. It might be seeing schools of flying fish. It might be seeing pods of bait on the surface. It might include seeing gamefish breaking the surface chasing bait. Whatever the form, seeing bait in the area is great!  Think about it for a minute. You've come to an area that you know offers favorable conditions for gamefish. You are able to see the food source. What else does the fish need? The answer is nothing. They are going to be close.

The limitation of being able to see bait and know you are in the right area is your ability to visually see the bait. On a good day, you potentially could spot bait up to a couple of hundred yards away. The good thing is that gamefish are not the only creatures feeding on baitfish. Marine mammals, particularly porpoise, are also good visual cues you are in the right area. Birds, however are the best opportunity to use visual cues to locate baitfish in a promising area. Like you and the gamefish, birds are only out there looking for something to eat. Using binoculars or even radar, you use birds to lead you to the baitfish. Once you have located bait in an area with favorable conditions, you have to be confident that gamefish are in your immediate area. If you aren't confident, then you end up running from area to area hoping for success without really curing the underlying issues. At this point, be patient and confident. 

Hopefully the information presented has been helpful. Feel free to reach out with any feedback. TrollTrue also offers a unique line of trolling lures designed to present natural baits in the most realistic manner possible. Finding fish is step one and the next step is getting them on the line.