Martyr CMDIVERHA Heavy Hull Plate Anode — Aluminum | 1″ × 6″ × 12″ | Salt & Brackish Water

Martyr CMDIVERHA — Heavy Hull Plate Anode | Aluminum | 1″ × 6″ × 12″ | Salt & Brackish Water

Part Number: CMDIVERHA (SKU: 194-CMDIVERHA)
Brand: Martyr Anodes
Official Product Type: Heavy Hull Plate Sacrificial Anode — Aluminum
Common Name: Diver’s Dream Heavy Hull Anode
Dimensions: 1″ × 6″ × 12″ (approx. 25.4 mm × 152 mm × 305 mm)
Supersedes: No known superseded number
Replaced By: CMDIVERHA is the current active part number

The Martyr CMDIVERHA is the heavy-duty version of the Diver’s Dream hull plate anode — double the thickness of the standard CMDIVERA at 1″ versus ½″. This increased mass means significantly more anode material and a longer service life between replacements, making it the preferred choice for vessels with high protection demands, extended haul-out intervals, or large areas of bare metal hull. Aluminum alloy construction makes this the correct choice for salt and brackish water environments.

Compatible Applications

• Steel and aluminum boat hulls with high cathodic protection requirements
• Commercial vessels, workboats, and fishing vessels kept in the water year-round
• Vessels with extended haul-out intervals where longer anode life is needed
• Large hull surface areas requiring maximum anode mass per mounting position
• Any hull surface in salt or brackish water where the standard ½″ plate anode depletes too quickly

CMDIVERHA vs CMDIVERA — Which Thickness?

• CMDIVERHA — 1″ thick (this anode): Double the anode mass, longer service life. Best for commercial use, high-demand applications, or extended intervals between diver inspections.
• CMDIVERA — ½″ thick: Standard weight, suitable for most recreational vessels — see Martyr CMDIVERA Aluminum Hull Plate Anode

System & Location

Cathodic protection system — hull-mounted plate anode. Mounts flush to the hull below the waterline using through-bolts or studs. The flat profile minimizes drag while the increased thickness provides substantially more anode material than the standard ½″ version. Designed to be replaced in-water by a diver.

Anode Material Guide

• Aluminum (this anode): Salt water & brackish water ✓
• Zinc: Salt water — see Martyr CMDIVERH Hull Anode — Zinc (1″ × 6″ × 12″)

Kit Contents

• One (1) aluminum heavy hull plate anode, 1″ × 6″ × 12″
• Mounting hardware not confirmed included — verify at time of order; reuse existing studs or through-bolts if not supplied

Dimensions & Weight

• Dimensions: 1″ × 6″ × 12″ (25.4 mm × 152 mm × 305 mm)
• Weight: Approx. 2,200 g / 4.85 lb (estimated)

Service Interval

Inspect at every haul-out or have a diver inspect at least annually if the vessel is kept in the water. Replace when the anode has been consumed to approximately 50% of its original mass. The increased thickness of the CMDIVERHA means it will typically last significantly longer than the standard ½″ version before reaching the replacement threshold — exact depletion rate depends on water conditions, current density, and the amount of bare metal being protected.

Installation Notes

• Mount flush to the hull using through-bolts or studs — ensure direct metal-to-metal contact between the anode and the hull
• Do not apply paint, bedding compound, or sealant between the anode and the hull surface
• Bare metal contact is essential for the anode to function correctly
• Torque fasteners securely — a loose anode will not make proper electrical contact and may be lost underway
• Use aluminum anodes in salt and brackish water only — not effective in fresh water

Technical FAQ

Q: What is the difference between CMDIVERHA and CMDIVERA?
The CMDIVERHA is 1″ thick; the CMDIVERA is ½″ thick. Both are the same 6″ × 12″ footprint. The heavier anode contains approximately twice the anode material, providing a longer service life before replacement is needed.

Q: Why aluminum instead of zinc for salt water?
Aluminum anodes are more electrochemically efficient than zinc in salt and brackish water, providing more protection per kilogram of anode material. They are the preferred choice for most salt and brackish water hull applications.

Q: Can this anode be used in fresh water?
No. Aluminum anodes do not perform correctly in fresh water. A magnesium anode is required for fresh water hull protection.

Q: How many anodes does my hull need?
The number and total mass of hull anodes required depends on hull material, surface area of bare metal, and water conditions. A marine surveyor or corrosion specialist can calculate the correct anode system for your vessel.

Related Parts

• Martyr CMDIVERA — Aluminum Hull Plate Anode, ½″ × 6″ × 12″ (Standard)
• Martyr CMDIVERH — Zinc Hull Plate Anode, 1″ × 6″ × 12″

Parts Desk Insights

The CMDIVERHA is the right choice for working vessels and commercial operators who want to extend the time between diver service calls. Doubling the anode thickness roughly doubles the service life at the same mounting position, which adds up quickly when you’re paying for diver time. For recreational boats on a regular annual haul-out schedule, the standard ½″ CMDIVERA is usually sufficient — the heavy version is most valuable where inspection intervals are longer or protection demands are higher. As with all hull anodes, getting the anode mass right for the vessel is worth a proper assessment rather than guessing.