How to Choose the Right Transducer: Thru-Hull vs Transom Mount vs In-Hull (CHIRP & Live Sonar)

By High Tide Supply Sonar Team • August 21, 2026

Your fishfinder multi-function display is only as good as the transducer sending crystal-clear acoustic pulses through the water column. Choosing between Thru-Hull, Transom Mount, or In-Hull options depends on your vessel's hull material, cruising speed, and targeted water depth.

1. Transducer Mounting Types Compared

Thru-Hull Mount

Installed through a drilled hole in the bottom of the hull with high-speed fairing blocks or flush tilt elements.

Best for Speed & Depth
Transom Mount

Bolted to the flat vertical transom of outboards and stern drives below the waterline.

Best for Trailer Boats
In-Hull (Shoot-Through)

Epoxied inside solid fiberglass hulls. No drag, no holes below waterline.

Solid Fiberglass Only

2. Understanding CHIRP Frequencies (High, Medium, Low)

Traditional single-frequency transducers send a single pulse (e.g. 200 kHz). CHIRP (Compressed High-Intensity Radiated Pulse) sweeps across a spectrum of frequencies, delivering superior target separation:

  • High CHIRP (150 – 250 kHz): Narrow beam, exceptional target resolution for shallow inshore waters (< 200 ft).
  • Medium CHIRP (80 – 130 kHz): Great balance of depth penetration and target detail for coastal waters (200 – 600 ft).
  • Low CHIRP (40 – 60 kHz): Maximum depth penetration for offshore pelagic species and deep dropping (> 1,000 ft).

Find the Exact Transducer for Your Boat

Filter by hull deadrise angle, power wattage, and multi-pin connector compatibility using High Tide Supply's Transducer Finder.

Open Transducer Finder Tool