Marine anodes, including zinc, aluminum, and magnesium anodes, are sacrificial metal components used to protect the hull and underwater metal parts of boats and yachts from galvanic corrosion. By corroding preferentially, the anodes help protect more valuable submerged components such as hull fittings, propeller shafts, rudders, trim tabs, and other bonded metal parts.
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1-2 weeks delivery time The Hollex Aluminium Ball Shaft Anode is a spherical sacrificial anode designed to protect boat propeller shafts against corrosion in brackish and saltwater environments. Its steel core helps prevent the anode from becoming loose around the shaft. Available for shaft diameters of 22, 25, 25.4 (1"), 30, 35, 38, 40, 45, 50 and 60 mm. Manufactured from aluminium, the anode features a split ball-shaped design for installation around the shaft. Supplied individually.
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$ 12.64
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1-2 weeks delivery time The Hollex Zinc Ring Propeller Shaft Anode is a ring-shaped sacrificial anode designed for corrosion protection of propeller shafts in saltwater environments. It is installed against the front of the propeller and is available in 20 variants for shaft diameters from 22 to 130 mm. Manufactured from zinc, the anodes have external diameters ranging from 60 to 210 mm, depending on the selected shaft size. The range includes versions with anode thicknesses of 15, 18, 29, 30, 40 and 60 mm. Select the appropriate version according to the shaft diameter and required anode dimensions.
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$ 9.26
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1-2 weeks delivery time Vetus SN complete propeller shaft nut sets with integrated replaceable zinc anode, available for VETUS propeller shafts from Ø25 to Ø60 mm. Each assembly combines the shaft nut, sacrificial zinc anode, lock washer, stainless-steel key and retaining screw. Versions are matched to specific shaft diameters and threads from M16x1.5 to M42x3, with replacement anodes available separately as SN25B through SN60B.
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$ 69.79
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1-2 weeks delivery time Vetus SN replacement zinc anodes for propeller shaft nut assemblies, available for shaft diameters from Ø25 to Ø60 mm. The range includes SN25B, SN30B, SN35B, SN40B, SN45B, SN50B and SN60B, with anode dimension B from 39 to 98.5 mm and weights from 140 to 1582 g. Designed as replaceable sacrificial zinc elements for compatible Vetus propeller shaft nut installations.
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$ 19.54
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1-2 weeks delivery time Vetus V-Quipment bolt-on sacrificial anodes available in aluminium and zinc versions with Ø90 x 45 mm body dimensions and an Ø8 mm central mounting hole. ALU08C is manufactured from aluminium-indium-zinc alloy to MIL-A-24779 (SH) specification and weighs approximately 0.47 kg, while ZINK8C is manufactured from zinc to MIL-A-18001K specification and weighs approximately 1.00 kg. Aluminium is intended mainly for freshwater use, while zinc is suitable for salt and brackish water.
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$ 34.60
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1-2 weeks delivery time Vetus V-Quipment aluminium bolt-on hull anodes for cathodic protection of underwater metal components, manufactured from aluminium-indium-zinc alloy to MIL-A-24779 (SH). Available in three sizes: ALU15C 150 x 70 x 25 mm at 0.49 kg, ALU25C 250 x 75 x 30 mm at 1.10 kg and ALU35C 300 x 80 x 35 mm at 2.10 kg. The anodes are intended primarily for vessels operating in fresh water and are installed using separate connection kits for steel, fibreglass or wooden hulls.
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$ 36.38
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1-2 weeks delivery time Vetus V-Quipment zinc bolt-on hull anodes for cathodic protection of underwater metal components in salt and brackish water. Manufactured from zinc to MIL-A-18001K specification, the range includes ZINK15C 150 x 70 x 25 mm at 0.98 kg, ZINK25C 250 x 75 x 30 mm at 2.50 kg and ZINK35C 350 x 80 x 35 mm at 4.70 kg. Each anode uses a two-point bolt-on mounting arrangement and requires separate connection kits for installation.
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$ 47.73
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1-2 weeks delivery time The MgDuff Aluminium Weld-On Anode is a rectangular sacrificial anode designed to protect boat hulls and rudders against corrosion. Available in three models: AD60 (320 × 125 × 25 mm) with a 380 mm welding strip, AD78 (305 × 76 × 32 mm) with a 385 mm welding strip and AD73 (356 × 152 × 32 mm) with a 456 mm welding strip. The aluminium body provides sacrificial corrosion protection, while the extended strip enables welded installation. Each model is supplied individually.
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$ 42.33
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1-2 weeks delivery time The MgDuff Aluminium Teardrop Weld-On Anode is a sacrificial anode designed to protect boat hulls and rudders against corrosion. Available in three models: AD76 (114 × 76 × 32 mm) with a 165 mm mounting strip, AD77 (157 × 83 × 41 mm) with a 230 mm strip and AD79 (171 × 83 × 41 mm) with a 230 mm strip. The AD77 and AD79 models feature a mounting hole spacing of 200 mm. Each anode has a teardrop-shaped aluminium body with an extended mounting strip and is supplied individually.
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$ 14.69
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1-2 weeks delivery time The MgDuff Zinc Teardrop Weld-On Anode is a sacrificial anode designed to protect boat hulls and rudders against galvanic corrosion in marine environments. Available in two models: ZD76 (114 × 76 × 32 mm) with a 160 mm mounting strip and ZD77 (157 × 83 × 41 mm) with a 230 mm mounting strip. The ZD77 version additionally specifies a mounting hole spacing of 200 mm. Both models feature a teardrop-shaped zinc body with an extended mounting strip and are supplied individually.
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$ 28.58
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1-2 weeks delivery time The MgDuff Zinc Weld-On Anode is a rectangular sacrificial anode designed to protect boat hulls and rudders against galvanic corrosion. Available in three models: ZD75 (100 × 45 × 28 mm) with a 152 mm mounting strip, ZD79 (171 × 83 × 41 mm) with a 230 mm mounting strip and ZD78 (305 × 76 × 32 mm) with a 385 mm mounting strip. The ZD79 model additionally features a mounting hole spacing of 200 mm. Each anode is manufactured from zinc and features an extended mounting strip for installation on the vessel. Supplied individually.
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$ 112.41
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1-2 weeks delivery time The MME Aluminium Rectangular Hull and Rudder Anodes are designed to provide sacrificial corrosion protection for steel-hulled boats in brackish and saltwater environments. The range includes six models with rectangular aluminium bodies measuring 305–457 mm in length, 68–102 mm in width and 38–64 mm in height. Available variants include MME13AB (305 × 68 × 38 mm), MME15AB (305 × 88 × 38 mm), MME26AB (450 × 102 × 40 mm), MME45AB and MME47AB (457 × 102 × 64 mm), and MME51AB (430 × 102 × 64 mm). The anodes feature cast-in mounting strips, with a specified strip length of 200 mm for MME13AB and MME15AB. All six models are intended for steel hull applications and are supplied individually.
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$ 118.22
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1-2 weeks delivery time E. Polipodio zinc shaft collar anodes for propeller shafts, supplied complete with screws and available for shaft diameters from Ø20 to Ø85 mm. Depending on the selected version, the outside diameter ranges from Ø60 to Ø140 mm and the anode height from 15 to 29 mm. The range includes 16 zinc (ZN) configurations for shaft diameters 20, 22, 25, 28, 30, 32, 35, 38, 40, 45, 50, 55, 60, 70, 80 and 85 mm. Select the required version according to the propeller shaft diameter and corresponding outside dimensions.
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$ 11.50
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1-2 weeks delivery time E. Polipodio zinc shaft collar anodes for marine shaft installations, available for shaft diameters from Ø18 to Ø85 mm. The range includes 16 zinc (ZN) models with shaft sizes of 18, 22, 25, 28, 30, 32, 35, 38, 40, 45, 50, 55, 70, 75, 80 and 85 mm. Depending on the selected version, the outside diameter ranges from Ø50 to Ø122 mm and the overall height from 47 to 108 mm. Select the required model primarily according to shaft diameter A and verify the corresponding outside diameter B and height H.
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$ 15.58
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1-2 weeks delivery time The Tecnoseal 00630FISH Series consists of suspended fish-shaped hang-on anodes supplied with a 6 m (19.65 ft) cable, available in Zinc 00630FISH, Aluminium 00630FISH-AL and Magnesium 00630FISH-MG versions. All three variants share the same dimensions of 237 mm length and 70 mm height. The Zinc version weighs 3.00 kg (6.61 lbs), the Aluminium version 1.18 kg (2.60 lbs), and the Magnesium version 0.76 kg (1.68 lbs).
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$ 132.49
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1-2 weeks delivery time Tecnoseal aluminium NACA-profile shaft collar sacrificial anodes, available in nine sizes for shafts from 19 to 35 mm, including metric and imperial shaft configurations. All models have a height of 25 mm, with outside diameters of Ø55 or Ø66 mm depending on size. The range covers shaft openings from 19 to 35 mm and aluminium anode weights from 0.07 to 0.12 kg. Select the required model according to shaft size, outside diameter and weight.
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$ 17.88
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1-2 weeks delivery time Tecnoseal aluminium shaft collar sacrificial anodes for shaft installations, available in Limited Clearance, Medium Size and Large Size configurations. The range includes metric and imperial shaft sizes from 19 mm / 3/4" up to 140 mm, with collar heights from 18 to 40 mm, overall diameters from Ø61 to Ø225 mm and weights from 0.02 to 2.20 kg. Compact Limited Clearance versions cover shaft sizes from 19 mm / 3/4" through 50 mm, including 7/8", 1", 1-1/8", 1-1/4" and 1-1/2" options. Additional medium and large aluminium versions are available for 60, 70, 75, 100, 120 and 140 mm shafts. Select the required model according to shaft size, collar height, overall diameter and weight.
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$ 14.28
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1-2 weeks delivery time Tecnoseal aluminium UK Type shaft sacrificial anodes for marine shaft installations, available in metric and imperial shaft configurations from 19 mm / 3/4" up to 50 mm. The range includes thirteen models with shaft openings from 19 to 50 mm, heights from 65 to 100 mm, overall diameters from Ø56 to Ø85 mm and aluminium anode weights from 0.22 to 0.952 kg. Imperial shaft options include 3/4", 7/8", 1", 1-1/8", 1-1/4", 1-1/2" and 1-3/4". Bolts and nuts are not included. Select the required model according to shaft size, height, overall diameter and weight.
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$ 51.71
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1-2 weeks delivery time Tecnoseal aluminium USA Type shaft sacrificial anodes for marine shaft installations, available in metric and imperial shaft sizes from 19 mm / 3/4" up to 76.20 mm / 3". The range includes compact models with 2 fastening holes and larger versions with 4 fastening holes. Depending on the model, weights range from 0.14 to 1.25 kg, heights from 51 to 102 mm and overall diameters from Ø54 to Ø122 mm. Available shaft sizes include 19, 25, 28, 30, 35, 40, 45, 48, 50 and 60 mm together with 3/4", 7/8", 1", 1-1/8", 1-1/4", 1-1/2", 1-3/4", 2", 2-1/4", 2-1/2", 2-3/4" and 3" configurations. Bolts and nuts are available on request. Select the required version according to shaft size, fastening configuration, height, overall diameter and weight.
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$ 21.73
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1-2 weeks delivery time Tecnoseal magnesium NACA-profile shaft collar sacrificial anodes, available in nine configurations for shaft sizes from 19 to 35 mm, including metric and imperial shaft dimensions. All models have a height of 25 mm, with outside diameters of Ø55 or Ø66 mm depending on size. Shaft openings range from 19 to 35 mm, while magnesium anode weights range from 0.06 to 0.10 kg. Select the required model according to shaft size, outside diameter, shaft opening and weight.
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$ 21.14
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How do Aluminum, Zinc, and Magnesium Anodes differ in protecting a boat?
Aluminum, zinc, and magnesium anodes all provide cathodic protection by acting as sacrificial metals, but their effectiveness depends on the water type and their electrochemical potential. Zinc anodes are traditionally used in saltwater and provide reliable protection in high-salinity environments. Aluminum anodes are more electrochemically active than zinc and offer a higher protective capacity for their weight, making them suitable for saltwater and brackish water and, with the correct alloy, many freshwater applications. Magnesium is the most active of the three materials and is primarily intended for freshwater, where its higher driving voltage provides effective protection in low-conductivity conditions. Magnesium anodes should generally not be used in saltwater or brackish water, as they may provide excessive protection and be consumed too rapidly.
Why is anode placement on the hull plate important for effective corrosion protection?
Correct anode placement is essential because sacrificial anodes must be electrically connected to the metal they protect and positioned where protective current can reach exposed underwater surfaces effectively. On metal hulls, anodes should be distributed around areas that are most susceptible to galvanic corrosion, including the hull plating, rudder, propeller shaft, stern gear, and other submerged metal components. Poorly positioned, undersized, or electrically isolated anodes may leave parts of the structure insufficiently protected. Proper distribution helps maintain a more uniform protective potential across the underwater metalwork and reduces the risk of localized corrosion.