If you’re anything like us, you love finding new spots in deep waters e.g. Wonky Holes (underwater springs). That’s why we’re here to talk about the Garmin GT51 transducer—a game-changer for any angler who’s serious about stepping up their fishing game. In this review, we’ll share how we’ve installed a dual pair of Garmin GT51 transducers in our 40 foot Black Watch Mood Swings and put it through its paces, and why it’s now a permanent part of our setup. Spoiler alert: it’s brilliant for finding Wonky Holes and so much more.
What Makes the Garmin GT51 Transducer Unique?
Let’s get straight to the good stuff: what makes the Garmin GT51 stand out? Here’s what I love about it:
For a start, the GT51 is a three in one transducer (SideVu, DownVu and 2D), however unlike other transducers, the GT51 has a power to frequency ratio ideal for offshore fishing.
- Lower Frequency Side Imaging: The GT51 operates at a lower frequency (260 kHz), which is perfect for deep-water fishing. Think about it as having x-ray vision for the ocean floor for depths out to 120 metres deep. It also has 455 kHz for intermediate depths.
- 500 Watts of Power: This thing’s a powerhouse, allowing you to spot underwater structures and fish like never before. So to give you an idea, in 100 metres of water, I can look for blemishes and structure out to 150 metres either side of the boat (300 metre coverage in total for that depth).
- SideVu and DownVu Imaging: SideVu is how you identify objects out to the side you can investigate, while DownVu gives you a better look of the true structure once you travel over the top of it.
- 600 Watts of 2D (medium freq.): Provides good fish recognition to 300 metres.
In other words, the three combined give you a really good idea of what is going on to recognise illusions. Hence I run the combo of all three.
Our Sounder Skills 1 course shows you how to troubleshoot some of these illusions and ensure you are always fishing on good fish.
For us, it’s a dream come true to track down Wonky Holes and other small objects. We love these honey holes in the middle of no-where as fish aggregate there and they are often unfished (being hard to find).
With the GT51, we can spot subtle underwater features up to 150 meters on either side of the boat in 100 meters of water. That’s next-level fishing, and it’s why this transducer is our go-to.
Here’s how to make sure you find those Honey Holes every time and don’t drive past them -> Wonky Holes Free Presentation!
Versatility of the Garmin GT51 Transducer for Smaller Boats
Not running a 40-footer? No worries. The Garmin GT51’s transom-mount version works like a charm on smaller boats. We’ve got one on our trusty blue boat and it’s just as effective for scanning shallower waters and finding hidden gems. Here’s what makes it great for smaller setups:
- Easy Installation: The transom-mount design is straightforward and doesn’t require specialized tools. Just make sure it’s positioned correctly to avoid turbulence interference.
- Compact Yet Powerful: Despite its size, the transom mount GT51 delivers the same SideVu and DownVu clarity as the through-hull model, making it a solid choice for outboard powered boats.
- Versatility: Whether you’re exploring outer reefs, or hunting for isolated spots, the GT51 adjusts seamlessly to give you detailed imaging.
Pro Tip: When installing on smaller boats, ensure the transducer sits just below the waterline and is angled almost parallel to the surface for accurate readings. A properly mounted unit means better reading at speed, clearer readings and less frustration on the water.
The Dual Pair Setup: Why Bigger Boats Need It
On our 40-foot Black Watch, the hull’s deep vee design posed a unique challenge. Enter the dual pair of Garmin GT51 transducers—our solution for full side coverage.
Here’s how we did it:
- One Transducer for Each Side: One GT51 looks left, the other looks right. No blind spots here.
- Y-Cable Connection: Both transducers are linked with a Y-cable, so the display is seamless on a single screen.
If you’ve got a big boat like ours with a deep V keel, this setup is a must. Smaller boats can usually get by with a single GT51 as it is mounted on the transom before the prop. But for shaft driven vessels, the turbulence from the props comes from under the hull, unlike an outboard, hence placement before the props is necessary.
In bigger boats, generally transducers cannot be mounted in the middle, due to the water filled bilges and difficult mounting areas.
Hence you need one on each side to look left and right as the hull obscures the signal to one side.
Look What the Garmin GT51 Transducer Found This Time!! Solid GOLD.
Tips for Getting the Most Out of Your Garmin GT51 Transducer
I’ve spent countless hours fine-tuning this setup, so here are a few tips to help you make the most of your Garmin GT51 transducer:
- Understand Side Imaging: The SideVu feature is a lifesaver for spotting ledges, rocks, and other fishy hangouts either side of you. Don’t just drive past potential hotspots—mark them and come back to assess them for fish with 2D.
- Tune Your Settings: Depth matters. The lower 260 kHz frequency will work best for deep water, while 455 kHz should be used in depths under 50 metres. Let me help you get the big picture when it comes to your Sounder unit with our FREE TRAINING!
- Install Correctly: Especially for dual setups, make sure the alignment is spot-on when cutting the angle on the fairing blocks. On larger boats seek professional advice before fitting the transducers. A poorly placed transducer can be an extremely expensive repair. For trailer boats be sure that the transducer is getting clean water (check for strakes and other obstructions forward of the transducer that may cause turbulence. Air turbulence is the biggest issue for broken transmissions.
- Regularly Clean the GT51 Transducer: Marine growth or debris on the transducer can distort the signal. Give it a quick clean before heading out to maintain peak performance.
- Use the Right Speed: The GT51 Transducer performs best at lower boat speeds when scanning. Reduce your speed to 4-6 knots when scouting for new spots.
- Mark Waypoints Wisely: Got a spot that looks promising? Drop a waypoint immediately. Trust us, your future self will thank you.
Searching in the Right Locations
I make no secret of the fact that I love finding new untouched spots using his Garmin GT51. Because these locations are unknown to many anglers and yield better catches of trophy fish. We have some free training that helps you see “The Big Picture” when it comes to your unit.
Remember: Nothing changes if nothing changes.
The video takes 20 minutes and then we have a 5 email “quick tips” series to help you get the most out of it.
Wrapping It Up: Why the Garmin GT51 Transducer Is a Winner
The Garmin GT51 transducer is, hands down, one of the best investments we’ve made for fishing deeper waters. Whether you’re running a big boat like Mood Swings or a smaller setup, this transducer’s clarity, range, and precision make it a must-have. With the right installation and a little know-how, you’ll be uncovering hidden fishing spots and landing trophy fish in no time.
Ready to level up? Check out our Free Sounder Training or Wonky Holes Free Presentation and start making the most of your fishing gear today!
