Rule Industries 51S 1500 GPH Automatic Bilge Pump 12V with Anti-Airlock

The Rule Industries 51S is a 1500 GPH fully automatic submersible bilge pump designed for reliable, hands-free bilge water removal aboard marine vessels. Operating on 12 Volts DC, this pump features computerized electronic sensing technology that eliminates the need for a separate float switch — the pump automatically checks for water every 2½ minutes and activates only when water is detected, then shuts off once the bilge is clear.

The 3-wire design supports a manual override or the addition of an indicator light, giving boaters added flexibility and control. With a 1-1/8" (28.6mm) discharge outlet and a draw of just 4.8 amps, the 51S delivers high pumping capacity with energy-efficient operation, consuming only minimal amp hours per day in check mode.

Key Features:

• 1500 GPH pumping capacity at open flow
• Computerized automatic operation — no float switch required
• 3-wire connection allows manual override or indicator light capability
• Activates at 5/8" water depth; drains down to 1/4"
• Fully submersible and ignition protected
• Double-insulated long-stack motor runs cooler and extends motor life
• No burn-out when run dry
• Moisture-tight PTFE seals prevent corrosion and leakage
• Anti-airlock protection for consistent priming
• Silent and vibrationless operation
• Double strainer with snap-lock base for easy cleaning and non-clogging protection
• Heat-resistant acetal resin housing
• Heavy-duty 5/16" stainless steel shaft
• Nylon/fiberglass impeller for durability and strength
• Marine-grade blocked wiring for corrosion resistance
• CE and ISO 8849 certified
• 3-year limited warranty

The Rule 51S is trusted by leading boatbuilders worldwide and is an industry-standard choice for vessels requiring dependable, low-maintenance bilge water management.