Attwood Marine Tsunami Mk2 T500 Livewell Aerator Pump, 12V, 500 GPH

Overview

The Attwood Marine Tsunami Mk2 T500 is a 12 V livewell aerator pump for keeping bait and catch supplied with fresh, moving water on fishing boats, skiffs, bay boats, and other small craft with livewell or baitwell plumbing. It sits in the 500 GPH class, with T500 pump data showing 507 GPH at 0 ft head under 13.6 V test conditions, a 3 A fuse rating, and a 3/4 in. barb outlet.

This parent product covers the T500 inlet configurations used to match different hull, seacock, and plumbing layouts. The Mk2 cartridge is serviceable with one hand, the outlet can rotate 360 degrees, and the pump supports installation with straight or 90-degree outlet routing where hose direction matters inside a tight bilge, transom, or livewell compartment.

The pump body is IP68 rated and built around materials selected for wet marine spaces, including a PC/PBT body and lid, nitrile seals, and an SS316 motor shaft. It is also listed against marine ignition protection and electrical wiring standards, which is important when the pump is mounted low in the boat near fuel systems, batteries, and other onboard electrical equipment.

Key features

• 12 V T500 aerator pump for livewell and baitwell water circulation.
• 500 GPH class output, with 507 GPH at 0 ft head and 319 GPH at 3.3 ft head under 13.6 V test conditions.
• 3 A fuse rating and 3/4 in. barb outlet for common livewell hose layouts.
• IP68 rated pump housing for wet bilge, transom, and livewell areas.
• 360-degree outlet rotation helps line up hose runs without forcing the pump body into an awkward position.
• One-handed serviceable motor cartridge helps make cleaning or replacement easier after regular baitwell use.
• Mk2 cartridges are compatible with previous Tsunami models, which helps when refreshing an older Attwood livewell setup.
• Meets ISO 8846 Marine ignition protection and ABYC E-11 and ISO 10133 marine electrical wiring standards.

Variants

This Tsunami Mk2 T500 range is offered with different inlet styles so the same pump family can suit several livewell plumbing arrangements.

The inlet configuration changes between variants. The core T500 specifications remain consistent across the 564X versions, including 12 V operation, the 3 A fuse rating, the 3/4 in. barb outlet, the 1-1/8 in. hole saw size, and the 500 GPH class pump output.

• 5640-4 - Straight inlet. This configuration uses a 3.5 in. long straight inlet with 3/4 NPS threading, which suits straight thru-hull runs where the pump can sit in line with the fitting.
• 5643-4 - 3/4 in. NPT inlet. This seacock version uses a 3/4 in. NPT inlet with a short 0.85 in. inlet length, which helps when the pump connects to a seacock-style fitting.
• 5644-4 - 90-degree inlet. This angled inlet helps route the pump where a straight approach would crowd hoses, bulkheads, or livewell plumbing.

Installation and setup

Match the inlet style to the existing hull fitting or seacock before ordering. The straight inlet version works well when there is room for a direct pump orientation, while the 90-degree inlet helps when the hose path needs to turn quickly after the inlet. The 3/4 in. NPT version is the configuration to consider where the installation is built around a compatible seacock connection.

The 360-degree outlet gives the installer more freedom to point the discharge hose without reworking the whole pump location. That matters in real boats, where livewell plumbing often shares space with steering lines, batteries, transom brackets, and wiring.

Electrical and system integration

This is a 12 V DC pump and should be wired with proper circuit protection using the specified 3 A fuse. As with any livewell pump, wiring should be kept above standing water where possible, supported against vibration, and protected from chafe near the transom, bilge, or livewell wall.

The pump is not a networked marine electronics device and does not connect to NMEA 2000 or NMEA 0183 systems. It is a straightforward livewell pump intended for switched 12 V operation as part of the boat’s plumbing and electrical system.

Use cases on board

This pump is a good match for anglers replacing or upgrading a 12 V Attwood Tsunami livewell aerator, especially where service access and inlet orientation matter. It fits common baitwell and livewell use on fishing boats that need dependable water movement during short runs, long days at anchor, or tournament-style catch care.