5 common types of interference for marine transducers

Your transducer may be one of the most important boat accessories that you own, but like any electronic piece of equipment, it is subject to interference from the other devices on your boat, as well as conditions in the water. No matter how strong the signal, at times you may find that the transducer just isn't delivering information correctly. If you're able to identify the type of interference you are dealing with, it may be easier to correct the problem.

According to Vexilar, a marine electronics manufacturer, there are five basic types of interference you'll be dealing with:

  • Acoustical: This occurs when the transducer was installed improperly so that the flow of water over its sensors is not even. 
  • Conducted: If you have a trolling motor attached to your boat, or your transducer itself is installed within the propeller hub of your trolling motor, your device may receive interference from the motor. You'll only have to deal with this issue if your trolling motor uses pulse width modulation (PWM) for speed control.
  • Electromagnetic Interference (EMI): Similar to conducted interference, this occurs when your trolling motor produces such powerful electromagnetic waves that they are absorbed by your transducer's wiring. 
  • Ignition: Just as it sounds, you can suffer from noise and interference caused by your ignition switch, which can distort not only your transducer signals but also those of your marine radio.
  • Sonar Cross-Talk: You may experience this problem if the signals from your transducer are intersecting with those of another one nearby that is transmitting at a similar frequency.

Marine electronic parts are becoming more powerful every day, which means that they're producing more interference. If you want to avoid these problems, the best way to do so is to make sure you're using high quality parts supplied by ePal, and that you have them installed by professionals who know what they're doing.

Clearing a fouled prop

After boating season is over, many boat owners will take their vessel out of the water only to find that the propeller is covered in barnacles, tangled plants, fishing gear and other debris that accumulated over the course of the summer months.

While it's tempting to simply leave your props alone and ignore the gunk and slime that gathers, this can have an adverse effect on your boat's efficiency. All of that material on the prop blade will cause it to move less water when it is spinning, and you'll end up using more fuel to cover the same distance.

In this article we'll discuss some of the ways you can clear a fouled prop:

  • Antifouling paint is sometimes applied to boat props while they're out of water for winter. You can apply it yourself, but many boatyards will do this work for you. This paint deters flora and fauna from gathering on the blades.
  • If your prop becomes entangled in some kind of fishing netting, such as a lobster trap, while you're underway, first stop the motor to assess the situation. With an outboard motor, you could tilt the engine up and untangle the netting by hand. For inboard engines, you can try running the motor in reverse to clear it. 

If your prop becomes unusable or corrodes because of debris, it may be time to invest in a new one. There are many places to purchase new boat parts, but you'll find the most affordable prices and the best service if you shop at ePal.

3 essential items every boater should have on their vessel

Reasonable people can disagree about what marine instruments are absolutely necessary for every boater. Indeed, the selection of equipment that you carry on your vessel depends largely on what it's being used for, whether you're a commercial fisherman or a recreational sailor. But there are certain tools and items that every boat should have, no matter what you plan to do once out on the water.

Here's a list of three essential items you shouldn't leave the dock without:

  • Jumper Cables: Just as you would keep a pair of jumper cables in your car in the event that its battery needs a jump, so should you make these a permanent fixture in your boat. Boating batteries can be unreliable, especially if they're old, so jumper cables protect you against an unexpected dead unit.
  • Personal Flotation Devices: Not only should you have one on board for every single passenger, but before pushing off you should make sure each member of your crew knows where these items are stored and how to use them. This is especially the case if traveling with less experienced boaters.
  • Spare Propeller: Having a spare prop can be a lifesaver in the event that the prop on your boat is damaged. This can happen if you accidentally hit underwater hazards that you didn't detect.

These are only three items that you should carry, but they're not the only ones. Having a solid arsenal of communication equipment, marine GPS and other products are just as important. If you're not sure what other tools you should be carrying, make sure to check out the ePal store to see what equipment is available.

Boating safety tips

Boating accidents don’t receive as much attention in the news as traffic accidents yet every year thousands of people lose their lives when boats collide, capsize in choppy waters, run aground, catch fire, or when they are tossed out of the boats. Most road accident-related deaths can be prevented if drivers and passengers observe simple safety procedures; boating deaths can similarly be avoided by exercising caution.

A motor vehicle requires regular service to keep it in good shape. The same applies to every type of boat out there. It is commonly believed that only the big passenger carrying boats require regular inspections and servicing and as such many an owner of a small boat evades the dry dock unless the boat has a problem he can’t fix on his own. Seasoned water vessel owners nonetheless emphasize the importance of regular inspection because during such exercises it is possible to detect and repair any problems that could put you and your crew at risk.

It is important to have some basic marine safety equipment on board every boat yet many boaters, especially owners of small boats, often go out to sea without any. It is rather unfortunate that such crews only appreciate the importance of having marine safety equipment aboard when they run into trouble and need to not only call for and direct rescuers to their positions but also to stay alive until help arrives. One piece of safety equipment that you should have with you is a marine GPS.  Not only does a marine GPS help you navigate the waters you are in but in case of emergency it is designed to help the user tell his/her locations’ exact coordinates. Even if you are stranded in the open waters and you’ve lost all sense of direction, a marine GPS should enable you to pinpoint your exact position so that a rescuer can find you.

Another important item of marine safety equipment is the life jacket. A life jacket is analogous to a car seat belt; believe it or not, most of the people who lose their lives in boating accidents are usually people not wearing life jackets. Wearing a life jacket can save your life in the event that your boat capsizes or you are forced to dive overboard. With a properly fitted life jacket you should be able to float with your head out of the water so that you continue breathing. You never know how long it will take before help arrives; even if you are a good swimmer you can get exhausted and drown before you are rescued.

Should you find yourself in the water a personal locator beacon (PBL) may mean the difference between life and death.  These small devices usually weigh less than a couple of powerbars.  They quickly and accurately relay your position to a worldwide network of search and rescue satellites.

Most of the marine safety equipment you need for safe boating is very affordable. A marine GPS, for example, may cost you less than $300.

How to find the best fishfinder for you – ePal Fishfinder Buyers Guide

There is nothing like the feeling of landing that prize fish. At ePal, we understand the complexity of buying a fishfinder; our buyer’s guide offers insight on how fishfinders work and what features to look for when purchasing one.

First let’s talk about what a fishfinder does and how it works. Fishfinders, also called depth finders, are tools that fishermen use to see what is under their boat. In order for a fishfinder to work, you must hook it up to a transducer. The transducer is the instrument that sends out sound waves which reflect off objects under your boat. Such objects include fish, the ground, vegetation, logs, rocks, and shipwrecks. The sound wave produces a signal that is sent back to the transducer which allows you see the objects represented on the screen. You can start to see why having a fishfinder onboard can greatly improve your odds of landing that prize fish. Now that we know how they work, let’s get into more specific details about what to look for in a fishfinder. I’m sure you’ve seen models that range in price from as low as $50 to an upwards of thousands of dollars. There are two key factors that make some pricier than others: the screen and type of transducer.


First, let’s take a look at transducers. As I mentioned above, this is the instrument that sends and receives the sound waves. When purchasing one, the first question we need to ask is what kind of material should I get? There are 2 popular types of materials:

1. Plastic housings: Plastic is usually more cost effective and recommended for metal and fiberglass hulls.

2. Bronze housing: These are usually pricier and recommended for wood and fiberglass hulls. As you know, wood can expand and cause damage to a plastic housing which could cause a leak.

The next question to answer is how should I mount the transducer? There are 4 different mounting options:

1. Transom mount: With this option, you would mount the transducer at the boats transom so it is directly in the water. These transducers are usually more cost friendly and pretty easy to install.

Transom Mount Install

2. In-Hull (or shoot-through): This kind of transducer is usually only used with fiberglass hulls and would be epoxied directly to the inside of your hull. Because the signal is transmitted through the hull of your boat, it will not be as strong as the other 3 methods. With this option, you would have a reduced depth reading and fish detection. There are, however, some plus sides to this though. First, you do not have to drill any holes in the hull of your boat and second it is very low maintenance.

In-Hull Transducer image

3. Through-Hull: There are 2 different kinds of through-hull transducer but we will look at the standard one first. With this kind of mount you would drill a hole in your hull and the transducer would protrude directly in the water. Through-hulls are recommended for displacement hulls and boats with straight-shaft inboard engines. They usually also come with a fairing block that allows for proper installation. Because of the way the transducer is installed, through-hull provides the best performance.

4. Tilted Element: This is the second kind of through-hull transducer. With this kind of mount you would also drill a hole in the bottom of your boat but unlike the standard through-hull you do not need a fairing block. This kind of transducer would mount flush against the hull and the element in the transducer acts as a leveling agent with the deadrise (or angle) of your hull.

Finally, let’s talk about power and frequency. Power is rated by watts RMS. The more powerful the sonar is, the deeper it can read and the clearer the readings will be. Just as an example, a 100 watt sonar can go to a depth of about 600 feet while a 500 watt sonar can get to about 1500 feet.

Frequency and cone width are your last transducer decision. Luckily for you, the manufactures usually pair the fishfinder with what they believe will be the best transducer for the job. So let’s look at a common transducer, the dual frequency 50/200KHz. This kind of transducer is normally used for salt water. Since water absorbs sound waves at a slower rate for lower frequencies, the 50KHz is used for deep readings and the 200KHz is used for shallower water, mostly up to 200 feet. It is important to remember that lower frequencies have a wider cone which also means that you get less target definition. Higher frequencies have a narrower cone but return much better detail and can detect smaller objects.


Next deciding factor is the display. This is where you will see the information the transducer receives. There are 3 main decisions you will need to make here:

1. Do you want a color screen?

The question is, do you choose color or monochrome. If you are on a budget, your best option is the monochrome or grayscale display. Grayscale displays are easy to read in the sunlight and can be purchased at a low price. Moving to a full color display will obviously give you more detail, allowing fish and structures to show up in different hues.  Click here to view all of our color fishfinders.  Click here for the Monochrome Fishfinders.

2. What resolution do you want?

Like any LCD screens now days, the detail comes with the amount of pixels you have on the screen. The more pixels you have packed on the screen the more realistic the image looks (think normal TV to an HDTV). A good example to look at would be the Garmin Echo 500C vs. the Garmin Echo 550C. They both have a 5 inch screen but the 500C has a 234 x 320 pixels resolution while the 550C is at 480 x 640 pixels.

3. What screen size do you want?

Last and certainly not least is screen size. A lot of factors play a role here so I hate to give advice without personally talking to my customers so I’ll just leave you with this: get the size that you will enjoy looking at, at the price you can afford. Something you many want to ask yourself before purchasing a fishfinder is if you want the ability to use a GPS on the same screen. This would allow you to purchase maps and save hotspots so you can easily find your way back to great locations. I will be doing a buyer’s guide for that in the future so look out for it!

There is one more thing I want to talk about before I end this buyer’s guide and that is some of the cool new technology available now. Both Lowrance and Humminbird have great new imaging setups. Lowrance calls theirs DSI and Structurescan and Humminbird calls theirs Down Imaging and 360 Imaging. Instead of the sonar images we are used to seeing on the screen these technologies give you a photo like view of what is under the boat. I would highly suggest getting a fishfinder with one of these technologies!

Thank you for taking the time to read this. If you have any questions about fishfinders please do not hesitate to give us a call or use the chat function at the bottom of your screen!