The Legend, Evolved

The WATERAX MARK-3® has been the gold standard in wildland firefighting for decades. The Watson Edition maintains that legendary performance while completely reimagining the user experience. At just 44 lbs—30% lighter than the previous generation—the Watson Edition delivers the same 380 PSI maximum pressure in a more compact, backpackable package.

The integrated carriage system with ergonomic padded straps reduces fatigue and injury risk during transport. A smart LED interface provides real-time engine status and troubleshooting, while Bluetooth connectivity lets you monitor performance via the MyWATERAX mobile app. The 4-stage centrifugal pump end delivers the high-pressure performance wildland firefighters depend on for initial attack, relay pumping, and mop-up operations.

Officially qualified to USDA Forest Service Specification 5100-274E, the MARK-3 Watson Edition meets the rigorous standards required by federal agencies and sets a new benchmark for high-pressure portable fire pumps.

Key Features

  • 30% Lighter, Backpackable

    At 44 lbs (20 kg), the Watson Edition is 30% lighter and 20% smaller than previous MARK-3 models. The integrated carriage system with padded straps lets you backpack the pump engine-side up or down.

  • Smart LED Interface

    Real-time engine status at a glance. The LED visual interface shows operating status, warm-up progress, and troubleshooting codes. High temperature protection automatically safeguards your engine.

  • Bluetooth Connectivity

    Monitor pump performance wirelessly with the MyWATERAX mobile app. Track engine speed, temperature, and runtime in real-time from your phone or tablet during operations.

  • Anti-Flooding Start System

    Anti-flooding technology significantly reduces the risk of flooding the engine during startup. Combined with 50% less pull force and a built-in foothold, starting has never been easier.

What Makes Watson Different

The Watson Edition improves on the MARK-3 legacy in four key areas: mobility, safety, ease of use, and ease of start.

  • Mobility

    30% lighter, 20% smaller
    Integrated carriage system with backpackable frame. Option to carry engine-side up or down. Integrated carry handle for quick loading and unloading. Just 44 lbs dry weight.

  • Safety

    Designed for firefighter protection
    Ergonomic carriage system reduces back injury risk. Padded straps protect shoulders from bruising. Muffler heat shield prevents burns. Lighter weight reduces slip, trip, and fall injuries.

  • User-Friendliness

    Smart and intuitive operation
    LED visual interface shows engine status and troubleshooting codes. High temperature protection. Bluetooth connectivity for real-time monitoring via MyWATERAX mobile app.

  • Ease of Start

    Starting has never been easier
    50% less force required for pull start. Built-in foothold improves steadiness. Engine warm-up indicator on LED display. Anti-flooding feature significantly reduces risk of flooding engine.

Performance Specifications

The 4-stage centrifugal pump delivers class-leading pressure for high-head applications and relay pumping.

  • Pump Performance

    Maximum Pressure: 380 PSI (26.2 BAR)
    Maximum Flow: 100 GPM (379 L/min)
    Maximum Head: 877 ft (267 m)
    Pump Type: Detachable 4-stage centrifugal

  • Flow at Pressure

    At 100 PSI: 80 GPM (303 L/min)
    At 150 PSI: 70 GPM (265 L/min)
    At 250 PSI: 40 GPM (151 L/min)

  • USDA Forest Service Qualified

    Specification: FSS 5100-274E
    Primary Pump Code: C-45-150/50
    Alternate Codes: C-45-175/40, C-45-200/40
    Tested: 100-hour endurance at San Dimas

Engine Specifications

  • WATERAX 140cc Engine

    Type: 2-cycle, air-cooled
    Displacement: 140cc
    Cylinder: Nikasil-lined
    Max Power: 10.7 HP (8 kW) @ 8,000 RPM
    Max Torque: 7.6 lb-ft (10 Nm) @ 7,050 RPM

  • Starting System

    Primary: Recoil starter
    Backup: Manual rope starter
    Pull Force: 50% less than previous models
    Features: Anti-flooding, warm-up indicator
    Foothold: Built-in for steadiness

  • Fuel & Compliance

    Fuel Type: 2-cycle premix gasoline
    Fuel Connector: SAE 45 (std) & Mercury adaptor
    Spark Arrestor: USDA Forest Service approved
    Sound Level: Max 107 dBA

Pump Specifications

  • Pump Construction

    Pump End: Detachable 4-stage centrifugal
    Max Intake Pressure: 200 PSI (13.8 BAR)
    Compatible With: Existing MARK-3 water-moving systems
    Interchangeable: With MARK-3 pump ends

  • Pump Connections

    Intake: 2" Male NPSH
    Discharge: 1.5" Male NPSH
    Thread Protector (Suction): 2" NPSH standard
    Thread Protector (Discharge): .25 Turn Forged with cap

  • Physical Specifications

    Dimensions: 21.6" x 12" x 14.6" (549 x 305 x 371 mm)
    Weight (dry): 44 lbs (20 kg)
    Frame: Integrated backpackable carriage
    Straps: Ergonomic padded shoulder straps

Applications

The MARK-3 Watson Edition delivers high-pressure performance for the most demanding wildland firefighting applications.

  • Initial Attack

    The backpackable design and quick-start features make the Watson Edition ideal for rapid deployment on initial attack. Deliver high-pressure water to knock down flames fast with pressures up to 380 PSI.

  • Relay Pumping

    With 877 ft maximum head, the MARK-3 Watson Edition excels at relay pumping operations in mountainous terrain. Chain multiple pumps to move water over long distances and elevation changes.

  • Mop-Up Operations

    The 4-stage pump delivers sustained pressure for thorough mop-up work. The lightweight design reduces firefighter fatigue during extended operations along the fire perimeter.

  • Remote & Helicopter Operations

    At 44 lbs, the Watson Edition is light enough for helicopter transport and sling operations. The integrated carry handle and backpack frame simplify loading and transport to remote locations.

Documents & Resources

  • Data Sheet

    Official WATERAX MARK-3 Watson Edition specifications, performance curves, and technical comparison with the MARK-3 185cc.

    Download PDF →

  • Quick Guide

    Fast reference for setup, priming, operation, LED status codes, and basic troubleshooting.

    Download PDF →

  • Product Brochure

    Complete overview of Watson Edition features, improvements, and capabilities with detailed photos.

    Download PDF →

  • Specification Document

    Detailed specifications for procurement and engineering documentation. USDA Forest Service qualification information.

    Download PDF →

Compare WATERAX Pumps

The MARK-3 Watson Edition delivers maximum pressure in a backpackable package—up to 380 PSI at 100 GPM. For lighter-duty applications, the MINI-STRIKER offers 170 PSI in an ultra-portable 13 lb unit. The STRIKER series provides 230-345 PSI with Honda 4-stroke engines for vehicle-mount and portable applications. The VERSAX series offers self-priming convenience at up to 150 PSI.

View All WATERAX Pumps

Complete Your Setup

The MARK-3 Watson Edition uses 2" NPSH intake and 1.5" NPSH discharge connections, compatible with standard forestry hose and fittings.

  • Forestry Hose

    1-1/2" and 1" forestry lay flat hose. EPDM-lined for durability with NPSH forestry couplings for direct connection to MARK-3 discharge.

    Shop Forestry Hose 

  • Fittings & Adapters

    NPSH couplings, wye valves, reducers, and adapters. 2" intake and 1-1/2" discharge compatible with MARK-3 connections.

    Shop Fittings 

  • Suction Hose & Strainers

    Foot valves and strainers for drafting from open water sources. NPSH connections for MARK-3 intake.

    Shop Footvalves & Strainers 

  • MARK-3 Parts & Tools

    Replacement parts, tool kits, mounting hardware, and accessories specifically for MARK-3 pumps. Keep your pump running at peak performance.

    Shop MARK-3 Parts 

Shop MARK-3 Watson Edition Accessories

MARK-3 Watson Edition (380 PSI, 100 GPM)

  • MK3-W MARK-3 Watson Edition

    The complete MARK-3 Watson Edition portable high-pressure fire pump. Includes SAE 45 fuel connector and Mercury adaptor. 380 PSI / 100 GPM. 44 lbs.

    View MK3-W 

  • Watson Edition Backpack Frame

    Integrated backpackable carriage system with ergonomic padded straps. Carries engine-side up or down. Reduces fatigue and back injury risk.

    View Backpack Frame 

  • Watson Edition Pump End

    4-stage centrifugal pump end for Watson Edition. Compatible with existing MARK-3 systems. Detachable design for easy maintenance and replacement.

    View Pump End 
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WATERAX

MARK-3® Watson Edition High-Pressure Fire Pump

$7,323.00 USD
$7,323.00 USD
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Shop Parts

Genuine WATERAX replacement parts ensure your pump delivers reliable performance season after season. From pump bodies and impellers to suction covers, mechanical seals, and shaft assemblies—we stock the components you need to maintain and service your pump.

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Need Help Selecting a Pump?

Whether you're outfitting a fire department, updating your agency's pump inventory, or selecting equipment for wildland operations, we can help you choose the right WATERAX pump for your application. The MARK-3 Watson Edition delivers the highest pressure in the most portable package—ideal for crews that need maximum performance in the backcountry.

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