---
product_id: 4139220
title: "Rule 35A Marine Rule-A-Matic Switch - 12V Automatic Bilge Pump Switch - Mercury Free, Durable, Reliable, and Easy to Install"
brand: "rule"
price: "€ 62.69"
currency: EUR
in_stock: true
reviews_count: 13
category: "Rule"
url: https://www.desertcart.fr/products/4139220-rule-35a-marine-rule-a-matic-switch-12v-automatic-bilge
store_origin: FR
region: France
---

# Marine-grade durability 12V DC power compatibility Easy, tool-free installation Rule 35A Marine Rule-A-Matic Switch - 12V Automatic Bilge Pump Switch - Mercury Free, Durable, Reliable, and Easy to Install

**Brand:** rule
**Price:** € 62.69
**Availability:** ✅ In Stock

## Summary

> ⚓ Stay dry, stay confident—Rule 35A keeps your bilge in check effortlessly!

## Quick Answers

- **What is this?** Rule 35A Marine Rule-A-Matic Switch - 12V Automatic Bilge Pump Switch - Mercury Free, Durable, Reliable, and Easy to Install by rule
- **How much does it cost?** € 62.69 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.fr](https://www.desertcart.fr/products/4139220-rule-35a-marine-rule-a-matic-switch-12v-automatic-bilge)

## Best For

- rule enthusiasts

## Why This Product

- Trusted rule brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Plug & Play Simplicity:** Quick, hassle-free installation with clear instructions—get your boat protected in no time.
- • **Hands-Free Water Defense:** Automatically activates your bilge pump at rising water levels—never worry about flooding again.
- • **Built to Brave the Elements:** Mercury-free, corrosion-resistant design ensures long-lasting performance in harsh marine environments.
- • **Trusted by Mariners Worldwide:** Proven reliability with 4.7-star rating and years of dependable service—join the savvy boat owners who never compromise.
- • **Precision Activation Every Time:** Float switch triggers exactly when needed, safeguarding your vessel whether docked or offshore.

## Overview

The Rule 35A Marine Rule-A-Matic Switch is a 12V automatic bilge pump float switch designed for reliable, hands-free water management on boats. Featuring mercury-free, corrosion-resistant marine-grade materials, it ensures durability in saltwater and freshwater environments. Easy to install and engineered for precise activation, this switch protects vessels from flooding by automatically triggering the bilge pump at rising water levels. Trusted by boaters for over two decades, it offers peace of mind with a 2-year warranty and a strong reputation for long-term performance.

## Description

Ensure your boat stays dry and protected with the Rule 35A Marine Rule-A-Matic Switch, a trusted solution for automatic bilge pump activation. Designed for seamless operation, this float switch automatically engages your bilge pump when water levels rise, providing hands-free water management and reducing the risk of flooding. Built with marine-grade materials, the mercury free Rule 35A is resistant to corrosion and harsh conditions, ensuring long-term durability and reliable performance in saltwater and freshwater environments. Its easy installation process makes it a practical choice for boat owners looking for a dependable, no-fuss solution to bilge water control. Whether you're a casual boater or a seasoned mariner, the Rule 35A Automatic Bilge Pump Switch offers peace of mind by keeping your bilge dry and your vessel safe. Pair it with a compatible 12V bilge pump for effortless water management on every journey.

Review: Feels solid and well made. - I have not yet installed it but the switch feels solid clicks so should be reliable, the hinge feels quality, small enough to fit almost everywhere. Vires are marine grade. Would buy again.
Review: Best if normally kept dry. - 8 Years so far. has worked very well. The trick to longevity is to place in a dry location. The float should trigger only as unusual water level is encountered. bolting it to the lowest point of the bilge where it will be forever submerged is probably the reason many are failing so early. Default to a location that indicates high water without needing to be wet all the time, and this will last many years. A small shim below giving some clearance from normal bilge height will go a long way.

## Features

- Reliable Automatic Bilge Control: The Rule 35A Marine Rule-A-Matic Switch ensures automatic activation of your bilge pump when water levels rise, preventing manual checks and safeguarding your vessel against unexpected water accumulation.
- Durable, Marine-Grade Construction: Built to withstand harsh marine environments, this bilge pump switch is mercury free and features corrosion-resistant components, including a robust housing and high-quality wiring, ensuring long-lasting performance.
- Easy Installation for Hassle-Free Use: Designed for straightforward setup, the Rule-A-Matic switch integrates seamlessly into your boat's bilge system. With simple wiring and clear instructions, installation is quick and convenient.
- Dependable Performance in Every Condition: Engineered for reliability, this float switch activates your bilge pump precisely when needed, ensuring smooth operation whether you’re at the dock or on open water.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B000O8DA3M |
| Batteries Included? | No |
| Batteries Required? | No |
| Best Sellers Rank | #7,359 in Sports & Outdoors ( See Top 100 in Sports & Outdoors ) #3 in Boat Bilge Pumps |
| Brand | Rule |
| Color | White |
| Customer Reviews | 4.7 4.7 out of 5 stars (1,655) |
| Date First Available | October 1, 2001 |
| Global Trade Identification Number | 00042237095435 |
| Included Components | Rule 35A Rule-A-Matic Float Switch - 12-24 VDC |
| Is Discontinued By Manufacturer | No |
| Item Package Quantity | 1 |
| Item Weight | 4 ounces |
| Item model number | 35 |
| Manufacturer | Rule |
| Material | Plastic |
| Part Number | RM500B |
| Power Source | Corded Electric |
| Product Dimensions | 3.5"L x 5"W x 8.25"H |
| Size | Rule 35A Rule-A-Matic Bilge Pump Float Switch, Mercury Free |
| Special Features | Not_Performance_Used |
| Style | Bilge Pumps Switches |
| Switch Style | Float Switch |
| UPC | 696582485641 042237095435 617297076870 666668135845 042237083722 071030261204 773975400198 611104328671 779421381288 042237106230 014445389231 012304410966 826713868894 675904094815 072090742719 826713868900 963041571116 |
| Voltage | 12 Volts (DC) |
| Warranty Description | 2 years |

## Product Details

- **Brand:** Rule
- **Color:** White
- **Global Trade Identification Number:** 00042237095435
- **Item Weight:** 0.25 Pounds
- **Manufacturer:** Rule
- **Material:** Plastic
- **Power Source:** Corded Electric
- **Product Dimensions:** 3.5"L x 5"W x 8.25"H
- **Style:** Bilge Pumps Switches
- **Voltage:** 12 Volts (DC)

## Images

![Rule 35A Marine Rule-A-Matic Switch - 12V Automatic Bilge Pump Switch - Mercury Free, Durable, Reliable, and Easy to Install - Image 1](https://m.media-amazon.com/images/I/41fUsHCz1QL.jpg)

## Available Options

This product comes in different **Style** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Feels solid and well made.
*by A***R on January 20, 2026*

I have not yet installed it but the switch feels solid clicks so should be reliable, the hinge feels quality, small enough to fit almost everywhere. Vires are marine grade. Would buy again.

### ⭐⭐⭐⭐⭐ Best if normally kept dry.
*by G***N on October 14, 2025*

8 Years so far. has worked very well. The trick to longevity is to place in a dry location. The float should trigger only as unusual water level is encountered. bolting it to the lowest point of the bilge where it will be forever submerged is probably the reason many are failing so early. Default to a location that indicates high water without needing to be wet all the time, and this will last many years. A small shim below giving some clearance from normal bilge height will go a long way.

### ⭐⭐⭐⭐⭐ Bad experience requires wise decisions
*by J***. on June 3, 2021*

This device is top of the line, at least that is my experience. Though recently I had some problems when at the same time a 2000 GPH pump failed within two months of use even though it has a four years warranty. Amazon Rep told me that I would need to contact the manufacturer because my time warranty through Amazon would be only 30 days and from then on...I would need to contact the manufacturer. ( somewhere in China ) I understand Amazon policy, but honestly I expected more from this Co. And then it occurred that a cheap float switch failed 48 hours after installation. But it happens that the cost of installation is at least three times the cost of the device. So, I decided to go for RULE....to be on the safe side. This is my recommendation. to whoever needsto replace a damaged float switch that are always located as deep and unaccesible as the boat builder could install them....

## Frequently Bought Together

- Rule 35A Marine Rule-A-Matic Switch (Mercury Free)
- Rule High-Performance 1500GPH, 12 Volt Water Pump for Boats - Bilge Pump with Pressure Switch, Submersible Pump, and Float Switch - Ideal for Marine Accessories, Boating supplies, and Bilge Pumps
- Rule 2000 GPH Bilge Pump 12V - Submersible Marine Boat Accessory with 1-1/8" Discharge, Anti-Airlock, Reliable Ignition Protection, Silent Operation, Easy-Clean Strainer - Rust/Corrosion Resistant

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*Product available on Desertcart France*
*Store origin: FR*
*Last updated: 2026-03-02*