Martyr CMGROUPERA Grouper Hanging Anode with 15' Cable — Aluminum | Salt & Brackish Water
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Martyr CMGROUPERA — Aluminum Grouper Hanging Anode with 15' Cable
Part Number: CMGROUPERA (SKU: 194-CMGROUPERA)
Brand: Martyr Anodes
Official Product Type: Sacrificial Hanging Anode — Aluminum
Supersedes: No known superseded number
Replaced By: CMGROUPERA is the current active part number
The Martyr CMGROUPERA is an aluminum sacrificial hanging anode designed to protect submerged metal structures — including boat hulls, dock pilings, crab pots, fish traps, and underwater frames — from galvanic corrosion. The 15-foot cable allows the anode to be suspended freely in the water column, maximizing surface exposure and protection coverage. Aluminum alloy construction makes this anode the correct choice for salt and brackish water environments.
Compatible Applications
- Boat hulls (hanging/suspended protection)
- Dock pilings and marina structures
- Crab pots, fish traps, and wire mesh traps
- Underwater frames, cages, and aquaculture equipment
- Any submerged metal structure in salt or brackish water requiring cathodic protection
System & Location
Cathodic protection system — standalone hanging/suspended anode. Deployed by suspending the anode from the cable into the water column adjacent to the structure being protected. Not mounted directly to the hull or drive.
Anode Material Guide
- Aluminum (this anode): Salt water and brackish water ✓
- Zinc: Salt water only — see Martyr CMGROUPER Zinc Grouper Anode
- Magnesium: Fresh water only
Kit Contents
- One (1) aluminum grouper hanging anode
- One (1) 15-foot (approx. 4.6 m) suspension cable
Dimensions & Weight
- Weight: 1,143 g / 2.52 lb
- Grouper / cylindrical hanging form factor
- Cable length: 15 feet (approx. 4.6 m)
Service Interval
Inspect at every haul-out or seasonal maintenance. Replace when the anode has been consumed to approximately 50% of its original mass. Do not allow anodes to deplete fully — an exhausted anode provides no protection. Aluminum anodes in active salt or brackish water environments typically last one full season depending on current density and water conditions.
Installation Notes
- Do not connect to a battery or any electrical source. This is a passive cathodic protection device only.
- Suspend the anode freely in the water column using the cable — do not allow it to rest on the bottom or against the hull.
- Ensure good electrical continuity between the anode cable and the metal structure being protected.
- Use aluminum anodes in salt and brackish water only. Aluminum anodes are not effective in fresh water.
Technical FAQ
Q: Why aluminum instead of zinc for salt water?
Aluminum anodes are more electrochemically active than zinc in salt and brackish water, providing more efficient protection per kilogram of anode material. They are the preferred choice for most salt and brackish water applications.
Q: Can I use this anode in fresh water?
No. Aluminum anodes do not perform correctly in fresh water. Use a magnesium anode for fresh water applications.
Q: What does "do not connect to battery" mean?
This anode works through passive galvanic action — it sacrifices itself to protect surrounding metal. Connecting it to a battery or impressed current system would interfere with this process and could cause damage.
Q: How do I know when to replace it?
Replace when approximately half the anode mass has been consumed. A fully depleted anode offers no protection.
Related Parts
- Martyr CMGROUPER — Zinc Grouper Hanging Anode with 15' Cable (Salt Water)
- Aluminum Hanging Anode 11ft Cable CMT-GROUPERA
Parts Desk Insights
The grouper-style hanging anode is one of the most practical solutions for protecting structures that can't be fitted with a bolt-on anode — traps, cages, dock pilings, and temporary moorings are the most common use cases we see. The most frequent issue customers run into is choosing the wrong alloy: aluminum is correct for salt and brackish water, but it won't work in fresh water. The second most common issue is letting the anode run to full depletion before replacing it — by that point, corrosion damage may already be underway. If you're unsure which anode material or size is right for your application, contact us before ordering.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.