Garmin GT56UHD-TM Transom Mount Transducer

The Garmin GT56UHD-TM Transom Mount Transducer (part 010-13073-00) is the all-in-one Ultra High-Definition transducer that delivers UHD ClearVu down imaging, UHD SideVu side imaging, and high wide CHIRP traditional sonar from a single transom-mountable body. Three scanning frequencies (455 kHz, 800 kHz, and 1 MHz) cover everything from deep-water search to high-detail close-in fishing. 500 watts of scanning sonar transmit power, 350 watts of CHIRP traditional power, the 25-foot cable that handles most typical install runs, and both transom and trolling motor mounts included in the box for install flexibility. For current-generation Garmin chartplotters that support the 12-pin UHD transducer interface, the GT56UHD-TM is the do-everything transducer.

What Ultra High-Definition (UHD) scanning sonar is. Garmin's refined high-frequency scanning sonar that delivers more detail and longer range than the previous-generation ClearVu and SideVu transducers. UHD adds the 1 MHz frequency on top of the older 455 and 800 kHz frequencies, with the 1 MHz frequency delivering 20 percent greater range than the previous generation while keeping the high-detail imagery that made ClearVu and SideVu the fishing-industry standards. For owners upgrading from older GT-series transducers, the UHD generation is a noticeable visible improvement in imagery quality.

Three scanning frequencies and what each one is for. 455 kHz: maximum range, deeper search capability, wider beam coverage, the right frequency for offshore work and for searching large areas. 800 kHz: balanced detail and range, the most-used frequency for typical inshore and shallow saltwater fishing. 1 MHz: maximum detail, shorter range, the right frequency for close-in structure fishing and for detailed bottom hardness identification. The transducer supports all three frequencies and switches automatically based on the chartplotter's configuration.

UHD SideVu side imaging shows the bottom and structure out to either side of the boat with photo-quality detail. At the 1 MHz frequency, you get the highest resolution at shorter range. At 455 kHz, you get up to 500 feet of coverage on each side at typical search depths. Combined with GPS waypointing, SideVu is the search tool that has changed how serious anglers fish: find structure on a search pass, mark the waypoint, come back and fish it.

UHD ClearVu down imaging shows photo-quality straight-down views of what's directly under the boat. Run ClearVu split-screen alongside CHIRP traditional sonar and you get both the high-detail structure view and the traditional fish-arch presentation simultaneously. ClearVu is especially useful for identifying brush piles, timber, weed mats, and other structure features that CHIRP traditional sonar interprets as ambiguous bottom returns.

High wide CHIRP traditional sonar at 150 to 240 kHz delivers traditional 2D fish-arch imagery with the CHIRP modulation that improves target separation. Up to 800 feet of depth in freshwater (saltwater depth varies with bottom conditions). The High Wide CHIRP designation refers to the wider beam pattern that covers more of the water column at any given depth, which is the right CHIRP design for searching the water column for suspended fish and bait balls.

The 12-pin connector is the modern Garmin transducer interface used on current-generation Garmin chartplotters. Compatible with ECHOMAP UHD2, ECHOMAP Ultra 2, GPSMAP plus generation, and other current Garmin units that have the 12-pin transducer port. For older Garmin units with 4-pin or 8-pin transducer ports, an adapter cable is required (sold separately) and feature support varies based on the older head unit's capabilities. Confirm chartplotter compatibility before ordering.

Built-in temperature sensor (no separate temp sensor needed). Temperature data shows on the chartplotter alongside depth and is the single most useful piece of data for finding feeding fish: most species have preferred temperature ranges and the boundaries between water masses are where the bait and the fish concentrate. The integrated temp sensor saves you from needing a separate transducer just for temperature.

Mounting flexibility. The transducer ships with both a transom mount kit and a trolling motor mount kit. Pick whichever install location matches your boat. Most bass and walleye anglers mount on the trolling motor for the bow-fishing perspective. Most center console and offshore anglers mount on the transom for the boat's main sonar feed. The 0 to 70 degree transom angle support means it fits the vast majority of recreational hull transom geometries.

The 25-foot cable is sized for typical small-to-medium boat installs where the chartplotter is at the helm and the transducer is on the transom or trolling motor. For larger boats with longer cable runs, Garmin sells extension cables sized to add reach. Extensions add some attenuation, so use the shortest cable run that works for your install.

Mounting on the transom. Pick a position on the transom about 7.5 inches from the prop centerline (further is better) and on the side that minimizes prop turbulence interference with the sonar beam. The transducer needs to sit so the bottom face is roughly level with the bottom of the hull at rest, with adjustment to keep it in clean water at planing speeds. Detailed install instructions are in the manual. Use stainless mounting hardware and marine-grade sealant on through-transom holes.

Mounting on the trolling motor. The included trolling motor mount kit attaches to most major brand trolling motor shafts. Position the transducer so it sits below the prop and faces straight down. The bow perspective from a trolling motor mount is what bass tournament anglers prefer because the bow fishing position is where you're actually working when you're casting at structure.

What this transducer isn't. It is not a thru-hull transducer (use a Garmin thru-hull for cruising sailboats and displacement powerboats that need flush bottom flow). It is not a Panoptix LiveScope transducer (those are the live-scanning forward-facing sonar transducers that require the LVS series of dedicated transducers and a Panoptix-compatible chartplotter or BlackBox). It is not the GT56 (without the UHD) or older GT54 (without UHD or 1 MHz support). For all-in-one transom or trolling motor mount sonar with current-generation Garmin chartplotters, the GT56UHD-TM is the right transducer.

2-Year Limited Garmin warranty. Same-day shipping before 3 PM ET on in-stock units.