Raymarine I50 Speed Package w/ST900/P120 Thru-Hull

Raymarine i50 Speed Pack | ST900/P120 Thru-Hull Suite

The Raymarine i50 Speed Package solves the challenge of high-precision velocity tracking by pairing the i50 digital display with the ST900/P120 high-sensitivity thru-hull transducer. Its core engineering leverages a low-friction paddlewheel to provide sub-second speed-through-water (STW), trip distance, and sea temperature data. By utilizing a dedicated signal path for surface telemetry, the system effectively eliminates the data-smoothing lag common in multi-function displays, providing a high-fidelity visual roadmap for performance-oriented sailors. This mechanical synergy is essential for identifying subtle current shifts, serving as a critical tactical node for calculating optimal leeway and course-over-ground (COG) in complex tidal environments.

From a system integration standpoint, you’ve got to ensure the P120 thru-hull is mounted in a “clean water” zone forward of the keel to prevent turbulence from corrupting the paddlewheel’s rotational frequency. I’ve found that speed “flicker” often occurs when the transducer face is fouled by marine growth; use the included blanking plug for seasonal cleaning without hauling the vessel. Ensure the SeaTalkng backbone is properly terminated to protect the i50’s internal microprocessor from data packet collisions. It’s also vital to calibrate the speed offset via a GPS reference to account for hull-specific boundary layer effects, as the i50’s internal logic requires an accurate baseline for valid distance log calculations.

Technical Specifications

• Display: Large-digit high-contrast speed LCD.
• Transducer: ST900/P120 high-sensitivity thru-hull.
• Telemetry: Speed, Log, Trip, and Temperature.
• Interface: SeaTalkng and NMEA 2000 data bus.
• Luminance: High-bright backlight for daylight visibility.
• Voltage: 12 VDC nominal bus power.
• Rating: IPX6 rated waterproof front panel.