Last updated: 07.07.2017. Added images and improved readability.
This guide is only focusing on castable and portable fish finders ( aside from explaining how fish finders work in general ). If you want more detailed information about finding a best fish finder overall check out this resource, if you are looking for kayak-specific advice – click here.
Although humans already caught fish for thousands of years before the first fish finders were invented, it’s much easier for modern anglers to catch when armed with high-quality electronics.
Fish finders provide a world of information to anglers, enabling them to understand what’s going on under the surface.
How do Fish Finders Work?
In the simplest terms, fish finders emit sound waves from a device called a transducer. These sound waves travel through the water until they eventually hit something and bounce back to the depth finder’s receiver.
The returned signal is then processed by a small computer which analyzes the strength of the returned signal and the time it took to hit the distant object and bounce back to the receiver.
This allows the computer to determine how far away different objects are — such as the lake bottom, creek channel, sunken tree or big bass. This information is displayed on various visual styles, allowing the angler to see what is going on under the surface.
Of course, there are also considerable variations among different fish finders. Some send their sonar signal in a single direction, while others bounce signals all over the lake. Some display their information in full color, while others only have a two-color screen.
Modern fish finder manufacturers are now offering another option that anglers should consider.
Though fish finders were historically considered semi-permanent additions to a boat, some manufacturers are now producing fishing sonars that are portable and some are even castable.
Sure, you could remove an old-style, fixed fish finder when upgrading or selling your boat, but it was more akin to a boat component than a tool for anglers. Meanwhile, these new portable fish finders can be carried around from one fishing spot to the next.
Portable vs Castable Units
The primary difference between castable and portable fish finders relates to their size.
Portable fish finders usually feature a small transducer that you can put in the water or attach to the bottom of your boat. It has a small display screen that shows the information obtained.
Castable fishing sonars feature a very small, yet rugged transducer, that you can attach to your fishing line. This allows you to cast it anywhere you like to get an idea of what is going on underneath the surface.
Some of these newer units lack a dedicated display. Instead, they simply send an image to your smartphone or tablet with the aid of an (usually free) app, Bluetooth, or WiFi.
Who Benefits most from Portable Fish Finders?
Portable fish finders work well in a variety of circumstances, but they are most helpful for anglers who fish from different types of boats and locations:
1. Kayaks, Canoes, Rental Boats
For example, you can attach a portable depth finder at the bottom of your kayak today before using it from a dock the next day. You can even attach it to a rented boat then remove it easily when you need to.
2. Ice Anglers
Portable fish finders are also suited for ice anglers who may want to inspect a dozen holes in the course of a day’s fishing. Fish finders provide more information than depth sounders do, making them a better choice for many anglers.
The only time they are not appropriate is for exceptionally large boats; in which case, the transducer needs to be too far away from the receiver.
Additionally, professional anglers or charter services may prefer a bigger and more feature-packed unit which is too large to make a suitable portable unit.
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Portable Fish Finders
Keep in mind that many companies make portability kits that feature a portable battery, a suction-cup mount for the transducer, and a carrying case. These kits can turn virtually any small fish finder into a portable tool.
|Product|| || ||
|Resolution||480 x 320 pixels||320V x 240H||320 x 240|
|Operating Frequency||Traditional: 50/77/200 kHz|
CHIRP (mid and high)
|Power Output: RMS||200 Watts||300 Watts||Max 180 Watts|
Garmin Striker 4 Portable Bundle
The Garmin Striker 4 Portable Bundle features a fully-functional, combination (GPS/fish finder) unit with a full-color, 3.5-inch screen. The entire kit only weighs 10.8 pounds so it is fairly easy to carry it with you around the lake.
You can use this model on a kayak, dock, or boat. It works in freshwater down to 1,600 feet and 750 feet in saltwater. It also measures water temperatures.
Humminbird 345c Portable
The Humminbird 345c Portable is a feature-packed fish finder that is easy to move from one boat to the next or as you make your way to the bank.
With 300 watts of RMS power output, it is a high-quality gear that works in water up to 1,000 feet deep. The 3.5-inch display features full-color support and crisp, easy-to-see images.
Lowrance Fish Finders
Several Lowrance models are available with portability packs, providing several options for anglers looking for a fish finder that they can move from one place to the next.
The Lowrance Hook 3x is their entry level unit, but it is still packed with plenty of great features. In addition to a full-color screen, it is backlit for your viewing pleasure.
Castable Fish Finders
Most handheld fish finders work in conjunction with your smartphone, rather than featuring a dedicated display unit. This is particularly useful for bank anglers.
|Product|| || ||
|Sonar Type||Depth scale & Fish depth||Dual beam||Piezo-Electric Ceramic Crystal|
|Depth Range||135 ft||130 ft||160 ft|
|Bluetooth Range||100 ft||140 ft - 160 ft||200 ft (Wifi range)|
|Battery Life||10+ hrs||up to 6 hrs||up to 10 hrs|
iBobber Bluetooth Smart
iBobber Bluetooth Smart is the smallest and lightest personal castable fish finder. It weighs about 1.7 ounces, so anglers using light-weight gear may want to bring along a heavier rig to cast the transducer.
It does not have a dedicated display unit so it simply sends the signal directly to your smartphone via a free app. It works in as much as 135 feet of water, but you have to keep it within 100 feet of your smartphone so that it can communicate with the device.
Deeper Smart Fishfinder 3.0
The Deeper Smart Fishfinder 3.0 is a dual-frequency transducer that uses Bluetooth technology to communicate with your iPhone or Android-compatible device.
It resembles a black fishing float but it is quite heavy at 3.5 ounces. It relies on a rechargeable 3.7-volt battery, which works for up to 6 hours of nonstop usage.
FishHunter Directional 3D
FishHunter Directional 3D operates in conjunction with your smartphone to display a high-quality, 3D image of the lake bed, as well as any fish lurking in the water. It has a WiFi range of 200 feet and a range depth of 160 feet.
It also features 5 independent transducers inside the float housing, enabling the unit to provide an exceptionally wide field of view as compared to other castable fish finders.
Portable fish finders are incredibly helpful tools for locating fish. They do not only expand your fishing horizons, but they also aid you to catch more fish. Review the recommended units above and pick one up today!