TIG Integrity — Transom Mounted Transducer Setup Guide [ summary version]

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QUICK REFERENCE — 6 Principles at a Glance

1. Get as close to the keel as possible — but keep outside prop diameter
2. Know where your strakes are — position between them, not behind them
3. Don't trust your welded transom plate — verify it against all principles
4. Your transom plate design could be working against you — try to attain a minimal gap from transom to transducer. touching is best[cant achieve with factory mount]
5. Transducer height — start with skim first, go lower if needed
6. Transducer angle — parallel to the water at chosen speed

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BEFORE YOU START — Which Side of the Boat?

	Detail
✅ Starboard is preferred	With a clockwise-spinning prop, wash can travel over slightly to port side however....
✅ Port is fine too	Hundreds of boats run port-side with zero issues and the distance from prop to typical transducer position is far away enough that the wash wont reach
💡 Why prop wash isn't the real concern	The boat moves forward faster than any disturbance can travel forwards toward the transducer
⚠️ EM fields	Generated at the powerhead (top of motor) — the lower unit has negligible EM output

⚠️ HINT: Never cable-tie other cables (lights, pumps, other transducers) to your transducer cable — run it separately to avoid picking up EM interference.

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PRINCIPLE 1 — Get as Close to the Keel as Possible

	Detail
✅ Do this	Mount as close to the keel as possible — it's the lowest point with the cleanest, most stable water flow
💡 Why	As the hull lifts onto the plane, a transducer mounted wide [outer boat]can break the surface and lose contact entirely. boat listing [ boat seesawing ] occurs in greater action the further out the transducer is situated.
⚠️ Watch out for	Transducer to sit outside the prop diameter — visualise the full trim range to confirm transducer turbulence trail does not affect prop performance.

⚠️ ATTENTION: Check motor at full turned lock in both directions across the full trim range — confirm the outboard cannot contact the transducer at any point.

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PRINCIPLE 2 — Know Where Your Strakes Are

	Detail
✅ Do this	Position the transducer between strakes, on the flat section of the hull.  Best to view over the back of the boat when underway to look for cleanest water.
💡 Why	Strakes tear up the water surface — a transducer sitting in that aerated stream generally will not produce a clean image
⚠️ Watch out for	Inlets, outlets, and thru-hull fittings upstream and inline — even a slight protrusion creates a turbulence trail

Aluminium pressed hull owners — read this:

• Pressed strakes run at close intervals and aerate the entire water surface layer
• Your transducer may need to run deeper than on a plate boat
• Transducer shape matters — a large 1KW brick-style transducer is a significant challenge on a pressed hull vs. a slim Garmin GT or Lowrance 3-in-1

💡 HINT: The weld bead where the hull meets the transom can cause aeration. Sand it smooth (100–180 grit, finish with 400 grit + lubrication) in the transducer position — but leave enough material to keep the join structurally sound.

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PRINCIPLE 3 — Don't Trust Your Welded Transom Plate

	Detail
✅ Do this	Apply all principles to your welded plate — don't assume it's correct because it's been welded in place
💡 Why	The fabricator knew how to weld, not necessarily where to place a transducer for speed reading
⚠️ Watch out for	Older boat welded plates could be designed for older transducers — Reading at speed and mounting brackets weren't the same or considered. back then .

Ask yourself:

• Is it as close to the keel as possible?
• Is it clear of strake turbulence?
• Is it clear of prop wash?
• Is it safe through the full trim and lock range?

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PRINCIPLE 4 — Your Transom Plate Design Could Be Working Against You

	Detail
✅ Ideal setup	No transom plate — transducer mounted directly against the transom is theoretically the best result however its your choice and sacrifice of read quality could result the further away your transducer is from the transom.
💡 Why gap matters	Every millimetre away from the transom introduces disturbed water and degrades the sonar image. This is especially important with side scan transducers where the motor leg could get in the way of the sonar signal.
⚠️ Watch out for: height	Angled folds at the lower edge of a plate raise the mounting surface — the transducer can't get low enough, and forcing it deeper exposes the fixing section of the mount to fast water, creating its own turbulence

💡 TIG Integrity mounts are designed to compensate for both gap distance and high transom plate positioning.

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PRINCIPLE 5 — Transducer Height

	Detail
✅ Starting point	Run a straight edge along the hull bottom — position the transducer so its face sits approximately halfway through its own thickness below that line
💡 Which side to measure from	Starboard transducer → measure from starboard side of transducer. Port transducer → reverse. The most water-exposed side is your reference
⚠️ Skimming caveat	A transducer perfectly placed at rest can lift clear of the water once the hull planes

When skimming doesn't work — go lower:

• Deeper keeps the transducer in contact through the hull's lifting motion
• Most people hit a wall here — they've run out of adjustment on the factory mount
• That's an equipment limitation, not a technique problem

⚠️ MAJOR POINT: A very common mistake I've seen in customer photos — the lower corner of the rear fixing plate, or the radiused rear section of the footprint plate, sitting below the hull line in fast water. This causes turbulence 100% of the time. No part of the mount should be below the hull line except the transducer itself.

💡 TIG Integrity mounts have longer arms specifically so you can go deeper without the rear plate digging into fast water.

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PRINCIPLE 6 — Transducer Angle

	Detail
✅ The goal	Transducer face parallel to the water at your chosen reading speed
💡 How to set it at home	Record your boat's running angle at speed with an angle finder → recreate that angle at home (jockey wheel + jack) → level the transducer with a spirit level
⚠️ No angle finder?	Search YouTube: "how to level your transducer with a level and coins" — but note these videos set it at rest, not at speed. An angle finder is more accurate and less messy especially when travelling at some speed.

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FIND YOUR BASE ANGLE (Critical)

Your boat is never at a fixed angle — speed, trim, wind, chop, and load all shift it constantly. Every hull is different: some ride bow-high, others push the nose down under load or at certain speeds. There is no universal correct angle.

What you need is a base angle — a consistent reference point chosen from:

• Your boat's typical running behaviour
• Your chosen fishing/reading speed
• Your average water conditions

Once established, adjust your transducer angle from that baseline. Think of it as dialling in for your most common scenario, not every possible one.

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FINAL CHECKLIST — Have You Covered Everything?

• ☐ Transducer positioned as close to the keel as possible
• ☐ Clear of all strakes and inline obstructions
• ☐ Transom plate position verified against all principles
• ☐ Transom plate design assessed — gap and height considered
• ☐ Height set and tested at speed — no part of the mount below hull line
• ☐ Angle dialled in at fishing speed, not at rest
• ☐ Base angle established from your typical conditions
• ☐ Transducer cable run separately from all other cables

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STILL NOT GETTING RESULTS?

You've worked through every principle. If results are still unsatisfactory, there is only one place left to go — deeper.

Below the surface turbulence, below the aeration, below the hull disturbance — the water is stable and perfect for sonar. The problem is getting there with a factory mount, which has a fixed adjustment range and wasn't built for the pressure and drag of real fishing speeds.

This is the gap TIG Integrity products were built to fill — deeper, closer to the transom, held firmly at speed with quick and easy positional adjustment.

Transducer Brand	Compatible Mount
Garmin GT	PELAGIC
Lowrance 3-in-1	Predator Heavy Duty Mount
Humminbird	Echo H-Duty Mount
Airmar 1KW	ABYSS Mount
Lowrance Active Image HD	A.I.M Transducer Mount

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📖 For the full detailed guide, visit:
https://tigintegrity.com.au/blogs/news/transducer-setup-secrets-complete-guide

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TIG Integrity — Built for the conditions a factory mount was never intended to handle.