Re: bilge water and transducers
Transducer type nomenclature:
Transom-mounted transducer: Transducer is externally mounted to the transom whereby the face of the transducer makes contact with the water. Typically, these are the most effective, the easiest to service, to adjust for an optimum sounding, easily replaceable and; of course, the most popular.
"Shoot-thru-the-hull-transducer: Transducer is mounted inside of the hull, usually in a bilge, sump or keel, permanently adhered to the hull or contained in a liquid reservoir. The sonar ping emitted from the transducer must penetrate a solid unblemished hull material to effectively record a sounding. The transducer has no contact with the water outside of the boat. These generally are installed to avoid having to drill holes in a transom below the waterline, for protection, and in most instances, will reduce the effectiveness of the sounding. Compromises are made in regards to eliminating a speed wheel, if equipped, recording water temperature and a reduction in sounding performance. This transducer is usually fixed with a bonding material and cannot be adjusted, serviced or changed without the likelihood of destroying it during removal.
Through-hull: Transducer is permanently installed in a "through-hull" hole whereby the face of the transducer is in contact with the water on the bottom side of the boat. It is usually faired to the deadrise so the its beam is parallel to the surface of the water. This transducer is fixed and cannot be adjusted. These are the most permanent of all types of transducers.
Captain Chris
SternMate?