The 4 Best Castable Sonar Fishfinders

Portable sonar units bring fish-finding technology to shorebound and small-boat anglers.

Dashboard-mounted sonar units help boat-based anglers catch more fish. So what are we landlubbers supposed to do? Now, thanks to personal sonar “bobbers,” fishermen on shorelines, docks, and piers can identify structure, bait, and gamefish.

These tennis-ball-size fish-finders can be cast or trolled and transmit what they see below to your phone or tablet. We put four units to the test.

bank fishing, shore fishing, portable sonar, portable fishfinder, castable fish finder

Connection: Bluetooth: iOS or Android smartphones or tablets
Sonar: Dual beam (290 kHz, 15 degree cone; 90 kHz, 55 degree)
Depth and r__ange: Effective to 130 feet deep; 150-foot range
Power: 6 hours per charge (USB cable and AC adapter)
Weight: 3.5 ounces
What's cool: Smart Imaging provides impressive sonar-mapping clarity for detailed bottom composition, including weeds growing off the bottom and realistic fish images tagged by depth. The dual-beam sonar allows users to grab broad views and then tighten the focus. We also liked the weather page, sun/moon data, fishing calendar, in-app camera, and social media integration.
($229; buydeeper.com)

Connection: Wifi: iOS or Android smartphones or tablets
Sonar: Single 30-degree beam (125 kHz)
Depth and r__ange: Effective to 120 feet deep; 300-foot range
Power: 4 hours per charge (USB cable with AC adapter)
Weight: 4 ounces
What's cool: One registered mobile device (master) controls the T-Pod's settings, but unlimited slave devices can monitor the same readings. That's a handy option for fishing in a group, teaching others, or simply canvassing broad areas. We also liked the fish alarm, shallow-water alarm, zoom bottom track, adjustable gain, and auto or manual depth range.
($130; sonarphone.mobi)

bank fishing, shore fishing, portable sonar, portable fishfinder, castable fish finder

Connection: Bluetooth: iOS or Android smartphones or tablets
Sonar: Single 90-degree beam (118 kHz)
Depth and range: Effective to 135 feet deep; 100-foot range
Power: 8 hours per charge (snap-in USB charging cradle)
Weight: 1.7 ounces
What's cool: The smallest of the personal sonar devices, this one can be deployed independently or used as a true bobber. With a snap swivel, you can clip your line to the upper attachment point and run a baited leader off the bottom. We also liked the depth-tagged fish icons that are color-coded by size, the GPS trip log, and the lunar calendar. The price point makes this a great entry-level unit.
($99; reelsonar.com)

bank fishing, shore fishing, portable sonar, portable fishfinder, castable fish finder

Connection: Wifi: iOS or Android smartphones or tablets
Sonar: Five dual-frequency transducers (381 kHz, 455 kHz)
Depth and range: Effective to 160 feet deep; 200-foot range
Power: 10 hours per charge, dual charger (AC adapter, car/boat plug)
Weight: 5.6 ounces
What's cool: The five view options available provide RAW Sonar data, 3D bottom contouring, 3D bottom mapping, an icefishing flasher, and directional casting. The latter uses all five transducers to display depth and location relevant to the unit's position. We also like that the maps were marked with fishing spots, navigational hazards, and marinas.
($249; fishhunter.com/home)

Did You Know?

▪ Personal sonar devices don't require cellphone service. Some connect via Bluetooth, others create their own wifi hotspot.
▪ Deploying multiple personal sonar units enables you to monitor several spots simultaneously (crappie brush piles, pier/bridge pilings).
▪ Some units allow users to share reports via social media.
▪ The split screen on the Deeper unit (below) depicts regular and flasher display.

Photographs by Cliff Gardner and John Keller