Czujnik prędkości/temperatury ST800-P120

This sensor is a dual-function model. It measures both:

The boat's speed through the water (speed over ground) via a paddlewheel. The water temperature.

No, this sensor is not directly compatible with modern instruments operating on an NMEA 2000 or SeaTalkNG network such as i70s displays or Axiom chartplotters. It is designed for older generations of Raymarine instruments.

Yes, this transducer is designed for through-hull installation. It is therefore essential to take the boat out of the water to drill the hull and perform the installation safely.

The ST800-P120 sensor body is made of plastic. This makes it suitable for installation on fiberglass or metal hulls.

This sensor is specifically designed to be compatible with older generations of Raymarine instruments, including the ST series such as ST40, ST50, ST60, ST60+ and ST290 displays.

The sensor is supplied with a permanently attached cable 13.8 m long, providing sufficient flexibility for connection to your onboard instruments.

Installing the P120 through-hull fitting requires drilling a 51 mm (2 inch) hole in the hull. It is essential to maintain this diameter to ensure a correct and watertight installation.

Yes, absolutely. The plastic body of this sensor is ideal for metal hulls (aluminum or steel) as it prevents any risk of galvanic corrosion that could occur with a bronze sensor.

The transducer uses a small paddlewheel that spins as the boat moves through the water. The rotation speed of this wheel is converted into speed data sent to the display.

Yes, this sensor’s design allows you to remove the insert (the part with the impeller) from its through-hull while the boat is in the water. The through-hull is fitted with a self-sealing valve that limits water ingress, letting you clean the impeller or replace the insert with a blanking plug.

This product is considered "obsolete" as it is designed for older navigation systems and does not use modern communication protocols (such as NMEA 2000 / SeaTalkNG). It primarily serves as a spare part to maintain existing installations.

Yes, electronically it is compatible and can replace a bronze model. However, the through-hull fitting is different. If you are replacing an existing bronze sensor, you must also replace the bronze through-hull fitting with the supplied plastic one. Ensure the drilling diameter is compatible.

Yes, orientation is critical. The sensor has an arrow that must point toward the bow of the boat. Incorrect orientation will completely skew speed measurements.

Yes, the sensor body is made of robust plastic, a material perfectly suited and resistant to the marine environment, including prolonged use in salt water.

Yes, this sensor with its plastic through-hull fitting is perfectly suited for installation on fiberglass hulls, which is one of the most common applications.

Yes, sensors of this type are usually supplied with a blanking plug. This plug allows you to replace the sensor's insert when the boat remains in the water for long periods of inactivity, to prevent marine organisms from colonizing the impeller.

To ensure perfect watertightness, it is essential to use a high-quality marine-grade polyurethane sealant or gasket, such as Sikaflex-291i or an equivalent product. Apply it generously around the through-hull fitting, under the flange, and on the threads before tightening the nut.

No, this sensor is not connected via NMEA 2000 or SeaTalkNG. It uses a proprietary connection designed for specific inputs on Raymarine instruments in the ST series (ST40, ST60, etc.).

The "P120" reference refers to the type of through-hull fitting. It is a low-profile plastic model (the letter 'P' stands for 'Plastic') designed by Airmar, the manufacturer of many sensors for Raymarine.

Yes, it can replace an old speed-only transducer. If your Raymarine ST instrument has a temperature input, you will get this new data. If it does not, the temperature function of the transducer will be ignored, and the speed function will work normally.