Simrad B45 Bronze Thru-Hull 9-Pin

The Simrad B45 Bronze Thru-Hull 9-Pin transducer is a dual-frequency depth and temperature sensor designed for serious anglers and boaters who demand reliable sonar data in freshwater and light saltwater environments. Built from marine-grade bronze, this thru-hull transducer installs permanently below the waterline to provide consistent bottom detection and water temperature readings without the noise or beam spread limitations of older single-frequency designs. If you're running a Simrad fishfinder system and need accurate structural mapping and thermal data, the B45 delivers the performance foundation that separates consistent catches from wasted fuel and fruitless hours on the water.

This transducer operates on 50 kHz and 200 kHz sonar frequencies, giving you the flexibility to switch between wide-beam low-frequency imaging for structure and shallow-water detail, and narrow-beam high-frequency returns for precise target separation and hard bottom definition. The bronze housing resists corrosion in saltwater spray and extended immersion, while the 9-pin connector integrates seamlessly with Simrad's xSonic and modern fishfinder networks. Weighing 3.6 pounds, the B45 is engineered for permanent mounting through the boat hull, where it remains stable at speed and delivers temperature-compensated depth readings regardless of cruising conditions or water density changes.

The B45 Bronze Thru-Hull works best on center-console boats, cruisers, and larger bass or walleye rigs where you've already committed to a Simrad sonar system and need multi-frequency capability without the maintenance burden of transducers mounted on the transom. Installation requires drilling a thru-hull hole and securing the bronze assembly from inside the boat—a permanent solution that avoids the vibration, cavitation, and signal loss common to skeg-mounted alternatives. Whether you're mapping new structure, monitoring seasonal temperature layers, or simply verifying bottom hardness before dropping anchor, the dual-frequency B45 gives your Simrad display the raw data needed to make confident fishing decisions.