The Rule 51S 1500 GPH Automatic Bilge Pump is an intelligent, high-capacity water removal system designed for boats that need reliable, autonomous protection. Unlike manual pumps, the 51S uses computerized water-sensing technology to monitor your bilge without the need for a bulky external float switch.

Intelligent Automatic Operation

• Computerized Cycling: The pump "wakes up" every 2.5 minutes for approximately one second. If it senses resistance against the impeller (indicating water is present), it continues to pump until the bilge is dry.

• Energy Efficient: Despite constant monitoring, the sensing mode is remarkably low-impact, consuming only about 0.35 Amp hours per day.

• Manual Override: Features a 3-wire configuration, allowing you to connect a manual override switch or an indicator light to see when the pump is active.

Key Performance & Durability

• High-Flow Capacity: Moves up to 1500 Gallons Per Hour (GPH), making it ideal for larger bilge compartments.

• Dry-Run Protection: Engineered to run dry without motor burnout, protecting your investment if the water runs out before the cycle ends.

• Rugged Marine Build: Includes a stainless steel shaft, moisture-tight seals, and ignition protection for safe operation in engine compartments.

• Easy Maintenance: The snap-lock strainer base allows for quick removal and cleaning of debris.

Technical Specifications

• Flow Rate: 1500 GPH (5678 LPH)

• Voltage: 12V DC

• Amp Draw: 4.8 Amps (at 12V)

• Fuse Size: 10 Amp

• Discharge Port: 1-1/8" (28.6mm)

Choosing the Right Model

If you prefer a system that only turns on when a physical float is lifted (rather than cycling every few minutes), you might consider the Rule-Mate series.