6 picks with specs, filters and a calculator to find the right size.
Bigger screens and live sonar show more but draw more power. Our calculator turns each unit’s amp draw into hours on your battery.
A small, low-draw unit with built-in GPS for marking spots, CHIRP sonar and ClearVü scanning. Sold with the GT20 transducer.
Best for: Kayaks, ice fishing and small boats running on a small battery.
Check price on Amazon (paid link) Specs from woo.gpscentral.caA popular 7-inch unit with CHIRP, Down Imaging and MEGA Side Imaging for seeing structure off both sides of the boat, plus GPS.
Best for: Anglers who want side imaging without going to a big screen.
Check price on Amazon (paid link) Specs from jayssportinggoods.comA 7-inch touchscreen chartplotter with inland lake maps covering 18,000+ lakes, CHIRP, ClearVü and SideVü. It can run Garmin LiveScope later. Some listings include a transducer and some don’t, so check before you buy.
Best for: Boats that want maps and room to add live sonar later.
Check price on Amazon (paid link) Specs from thegpsstore.comA bright 9-inch screen at a mid-range price, with the TripleShot transducer and C-MAP Discover charts for the US and Canada. It draws only about two-thirds of an amp at full brightness.
Best for: A big screen without a big power draw.
Check price on Amazon (paid link) Specs from gpscentral.caA castable sonar ball that shows depth and fish on your phone over Wi-Fi up to about 390 feet away. It has its own battery, so it needs no boat power, and has shore and ice modes.
Best for: Shore anglers, ice fishing and rental boats.
Check price on Amazon (paid link) Specs from deepersonar.comLive sonar that shows fish moving in real time. It’s an add-on: the GLS 10 box and LVS34 transducer connect to a compatible Garmin display. At about 1.75 A typical on 12 V, it’s a real load to plan for.
Best for: Adding live sonar to a Garmin ECHOMAP or GPSMAP.
Check price on Amazon (paid link) Specs from defender.comNo products match those filters. Try clearing one.
Pictures are our own illustrations, not photos of the actual products. Specs come from the manufacturer or retailer listing linked on each card and were checked in October 2026. Models and prices change, so confirm details on the listing before you buy. As an Amazon Associate I earn from qualifying purchases.