Raymarine i50 Speed System, ST900/P120 Retractable Speed/Temp Thru-Hull Transducer, 12V, IPX6, SeaTalk ng, NMEA 2000

Overview

The Raymarine T70583 is an i50 Speed System supplied with an ST900/P120 retractable speed and temperature thru-hull transducer for monitoring boat speed, sea surface temperature, trip data, and log data from a dedicated marine instrument display.

The i50 Speed display is built for smaller helm and cockpit stations where readable data matters more than screen size. Its 110 mm x 115 mm x 44 mm display has oversized digits, red night backlighting, SeaTalkng networking, and direct transducer connections, so it can work as the main speed display for its own transducer or repeat data from a compatible network source.

The display runs from a 12 V DC supply with a 10 V DC to 16 V DC operating range and carries an IPX6 waterproof rating for exposed marine installations. The included ST900/P120 thru-hull transducer records speed and water temperature, uses a low-profile retractable housing, and supports routine paddlewheel maintenance without removing the whole fitting from the hull.

Key features

• i50 Speed display shows speed through water or speed over ground, sea surface temperature, trip data, and log data.
• Oversized LCD digits make speed and temperature readings easier to check from the helm during day running or at night.
• Red backlighting helps preserve night vision on evening passages and early-morning departures.
• SeaTalkng network-ready display supports integration with compatible Raymarine instruments, autopilots, SeaTalk systems, and NMEA 2000 networks with the correct adapters.
• Built-in speed and temperature transducer interface allows the display to operate as a master instrument with its own thru-hull sensor.
• ST900/P120 retractable thru-hull transducer records speed and temperature through a low-profile fitting with a 51 mm hole size.
• ST900 sensor speed range is 0.3 to 45 knots, with water temperature measurement from -10°C to 40°C.
• Low display power draw, with less than 1 W typical consumption for the display only and 2.4 W maximum with the transducer connected.
• Display supports surface mounting, with an optional trunnion mount kit available for installations where a bracketed display is preferred.

Installation and setup

This system suits RIBs, powerboats, and small yachts that need a dedicated speed readout without adding a larger multifunction display at the helm. The display has a compact footprint for bulkheads, dashboards, and cockpit panels, while the red backlighting and large numerals keep the main speed information easy to read in changing light.

The ST900/P120 transducer is a thru-hull sensor, so installation requires a suitable hull location, a 51 mm hole, correct bedding, and access inside the boat for the housing and cable run. Its retractable insert is useful on boats that need occasional cleaning of the paddlewheel because growth, debris, or trailering residue can affect speed readings.

Electrical and system integration

The i50 display is intended for 12 V DC boat systems and should be wired within its 10 V DC to 16 V DC operating range. Current draw is low, with 45 mA to 65 mA typical for the display only and up to 200 mA maximum when the transducer is connected.

For networked installations, the display includes two SeaTalkng connections and transducer connections. It can share data with compatible Raymarine equipment and can be adapted into SeaTalk or NMEA 2000 systems when the installation uses the proper network hardware.

Compatibility and fit

The ST900/P120 transducer is the plastic thru-hull version for fiberglass or metal hulls. It has analog output for compatible Raymarine instrument systems including i40, i50, iTC-5, and selected legacy systems, and the ST900 transducer core can be retrofitted into existing Airmar P120 and B120 housings where that housing compatibility applies.

This package is a practical match for boat owners replacing an older speed instrument, adding a dedicated speed and water temperature display, or building out a compact Raymarine instrument network on a small cruising boat, fishing boat, or performance sailboat.

What’s included

• i50 Instrument display
• ST900/P120 Speed/Temp transducer
• Suncover to match i70s, p70s, p70Rs, and eS Series
• Front bezel to match i70s, p70s, p70Rs, and eS Series
• Suncover to match a, c, and e Series
• Front bezel to match a, c, and e Series
• 400 mm SeaTalkng spur cable
• SeaTalkng blanking plug
• Gasket
• Fixing screws x4
• Documentation