Wesmar HD850 Series Sonar - 
The HD850 is the combination of new technology and quality engineering,  featuring a number of important new elements.
 
Active Stabilization-
 
The stabilization gyro is in the soundome, so  when the transducer scans, the gyro scans with it. Corrections are made in the  exact direction the transducer is looking, keeping the sound beam on target. The  Wesmar gyro runs 100% of the time. Other units have the sensor mounted to the  bulkhead, delaying response time.
Digital Link-
 
Long, interconnect cable runs are always subject to  noise and low sonar performance. Wesmar's new digital link between the sonar  electronics (near the transducer) and the computer console in the wheelhouse  operate noise free for maximum sonar performance.
Searchlight Advantage-
 
No Sonar ha better directivity than Wesmar  engineered transducers. One hundred percent of the transducer surface area  points in the direction of the fish in a sharp and narrow beam. Dispersed fish  and hard to mark fish are detected clutter-free. An Omni sonar, with a diffused  beam, allows dispersed fish and fish near the bottom to go undetected.
Split Screen Mode-
 
Scan forward and then across the bottom. This is  ideal for mid-water and bottom trawling. Head for the fish out in front and  watch as they pass to either side of the vessel. Sounders only mark under the  vessel and not to the sides, missing the target.
 Top part forward scan, lower part profile, each have separate adjustments.
Stabilized Down Sounder-
 
When the seas get rough, the best of sounders  lose track of the bottom. The HD850 in the down sounder mode, with active  stabilization on, will keep the sound beam where it should be: straight down.  Lower the hoist below the bubble layer for a ground picture unmatched by other  sounders. Fishing in the ice? Raise the transducer inside the sea chest, and the  Wesmar keeps running.
Linear Scan Mode-
Ideal for finding and tracking fish close to the  bottom. Linear scan mode presents a forward view of the bottom not available on  other sonar's. With this comes better differentiation between the bottom and  fish close to the bottom. In linear sonar presentation the sweep starts at the  left and moves to the right. Range is measured vertically, bearing along the  horizontal. When scanning for ground fish, the bottom will mark horizontally  across the screen and not a half circle.
Specifications-
 Frequency- 110 khz
 Hoist Height- 58.3 inches
 Minimum Seachest- 39.37 inches
 Retraction Time- 5 seconds
 Soundbeam- 4.2 Degrees V, 5.2 Degrees H