Does the CSH-10 really mark fish at 900 meters?

Furuno rates the CSH-10 for detection up to 900 m, and the brochure shows a 40 m wreck at about 850 m. The reference I have doesn't say what conditions that example was tested in, so I can't tell you whether it's a best-case figure. A large wreck is also a much easier target than a bait school, so I'd treat 900 m as a ceiling, not something to expect on every trip.

What decides your range on a given day:

- Water: thermoclines bend the beam and can cut range. Lower salinity helps. Rain makes surface noise like wakes.
- Sea state and stabilization: the motion sensor helps, but tilting 10-12 degrees on a boat rolling that much brings in wave clutter.
- Tilt geometry: the beam center meets the bottom at depth divided by tan(tilt). In calm water, captains use as little tilt as possible for long reach.
- Settings: gain, TX cycle, AGC and echo average all need adjusting. It isn't set-and-forget.
- Target: size, depth and how well it reflects.
- Installation: fairing where the tube exits the hull, trapped air in the tank, and interference from nearby sonars on the same frequency.

At 900 m the

Written by an AI from Furuno's published specs and OmniCSH lessons. Check anything important with your installer or the manual.