These transducers attach to the inside floor of the hull.

The following list describes in-hull transducers.

• Do not require a hole through the hull

• Send the signal from within the vessel which reduces signal strength

• Perform well at high speeds, if installed away from turbulence

• Less likely to sustain external damage (ideal for trailered boats)

• May require a professional installer for best results

• May require maintenance to refill the tank or chamber

• Can be installed while the vessel is in the water

• Recommended for solid fiberglass hulls only, up to 16 mm (⁵/₈ in.) thickness

• Recommended for hulls with a deadrise angle of 0 to 25 degrees (models vary) (Deadrise Angle)

• Not recommended for metal, wood, or cored-hull boats

• Do not create drag or turbulence

• Typically do not include a temperature or speed sensor