Attwood Marine Sahara MK2 Automatic Bilge Pump, X-Air Impeller, SteadySwitch

Overview

The Attwood Marine Sahara MK2 is an automatic bilge pump range for boats, with 500, 800, and 1200 GPH flow options available for 12V and 24V DC systems. It combines the pump and float switch in one unit, which keeps the bilge installation simpler than a separate pump and switch setup.

The Sahara MK2 uses Attwood's X-Air anti-airlock impeller to purge trapped air from the pump and discharge line, helping the pump keep moving water instead of running dry. It activates at 1-3/4 in. (50 mm) of water and shuts off at 3/4 in. (19 mm), which makes it useful for routine bilge water control in small powerboats, fishing boats, cruisers, and sailboats.

Retail versions in this range include a 29.5 in. (750 mm) wire length, an IP68 rating, and a check valve. The pump uses a PBT glass-filled impeller, SS316 motor shaft, and nitrile seals for service in wet bilge spaces where vibration, standing water, and saltwater exposure are part of normal boat use.

Key features

• Automatic bilge pump range with 500, 800, and 1200 GPH configurations for matching flow capacity to the vessel and bilge layout.
• 12V and 24V versions support common DC electrical systems used on small and mid-size boats.
• X-Air anti-airlock impeller helps clear trapped air from the pump and hose so the pump can continue moving water.
• Integrated mechanical float switch with microswitch starts pumping at 1-3/4 in. (50 mm) and shuts off at 3/4 in. (19 mm).
• IP68-rated construction with a PBT glass-filled impeller, SS316 motor shaft, and nitrile seals for wet bilge environments.
• SteadySwitch float control helps reduce rapid cycling, which can drain the battery and shorten pump service life.
• External mounting feet and a serviceable cartridge make access easier in tight bilge compartments.
• Meets or exceeds bilge pump, ignition protection, and marine electrical wiring standards including ABYC H-22, ISO 8849, ISO 15083, ISO 8846 Marine, ABYC C-1500, ABYC E-11, and ISO 10133.

Variants

The Sahara MK2 automatic bilge pump is offered in five configurations that vary by rated flow and DC voltage. The flow rating determines how much water the pump is rated to move, while the voltage must match the boat's bilge pump circuit.

Across the part numbers listed here, the automatic float operation, X-Air anti-airlock impeller, IP68 rating, 29.5 in. (750 mm) wire length, and included check valve remain consistent. Outlet barb sizes and fuse ratings vary by model.

• 5505-7: 500 GPH, 12V. This is the S500 version with a 3 amp fuse rating and 3/4 in. (19 mm) plus 1 in. (25 mm) hose barb outlet options, a practical size for smaller bilge compartments and routine water removal.
• 5508-7: 800 GPH, 12V. This S800 version uses a 5 amp fuse rating and the same 3/4 in. (19 mm) plus 1 in. (25 mm) hose barb outlet options, giving 12V boats more flow than the S500 while keeping similar hose connections.
• 5512-7: 1200 GPH, 12V. This S1200 version uses a 6 amp fuse rating with 1 in. (25 mm) and 1-1/8 in. (28 mm) hose barb outlet options, matching the higher flow capacity with larger discharge hose sizes.
• 5509-7: 800 GPH, 24V. This S800 version is for 24V DC bilge circuits, with a 2 amp fuse rating and 3/4 in. (19 mm) plus 1 in. (25 mm) hose barb outlet options.
• 5513-7: 1200 GPH, 24V. This S1200 version is the 24V configuration with a 3 amp fuse rating and 1 in. (25 mm) plus 1-1/8 in. (28 mm) hose barb outlet options for higher-capacity bilge discharge runs.

Installation and fit

The universal mounting pattern helps when replacing many common bilge pumps, especially in bilge spaces where drilling new holes or reaching mounting screws is difficult. The external mounting feet also make it easier to inspect or service the cartridge after installation.

For hose fitment, the S500 and S800 retail configurations support 3/4 in. (19 mm) and 1 in. (25 mm) barb outlets. The S1200 retail configurations support 1 in. (25 mm) and 1-1/8 in. (28 mm) barb outlets. Matching the outlet to the existing discharge hose helps reduce restrictions and keeps the installation cleaner.

Electrical and system integration

The pump voltage must match the vessel's DC system. The 12V models are used on typical small-boat electrical systems, while the 24V models suit vessels wired with 24V bilge circuits. Automotive blade type fuses are recommended, with fuse size set by model: 3 amp for S500 12V, 5 amp for S800 12V, 2 amp for S800 24V, 6 amp for S1200 12V, and 3 amp for S1200 24V.

The integrated automatic switch means the unit can manage normal bilge water without a separate float switch. As with any bilge pump, it should be installed with proper wiring protection, secure hose routing, and access for inspection, cleaning, and seasonal maintenance.

Use on board

This range works well for owners and builders who want an automatic bilge pump with straightforward service access and clear voltage and flow options. The lower-flow version suits smaller bilge areas, while the 800 and 1200 GPH versions fit boats that need more evacuation capacity within the same Sahara MK2 platform.