BENETEAU SHAFT ANODE 50mm

Function and technical context

Shaft anodes are cathodic protection elements designed to be mounted directly on the tail shaft of the vessel, acting as a sacrificial metal against galvanic corrosion that occurs in the marine environment. This aluminum-zinc alloy anode is specially sized for 50 mm axles, being a common solution in medium and large lengths of the Beneteau brand. By sacrificing itself electrically, the anode protects the shaft, horn, propeller and other submerged metal surfaces from accelerated oxidation caused by salt or brackish water. Without correct cathodic protection, galvanic corrosion can deteriorate high-cost components such as the propeller shaft, forcing unplanned groundings and costly repairs in the shipyard.

When to replace this part?

Shaft anodes must be inspected at least once a season and replaced when they have lost approximately 50% of their mass, since below that threshold the cathodic protection is insufficient. The symptoms of a depleted or missing anode are easily visible: pitting or corrosion marks on the stainless steel shaft, reddish or greenish discoloration in the horn area, and uneven wear on the propeller. It is recommended to replace the anode preventively at each annual stranding, even if the boat sails in waters with low conductivity, to guarantee continuous protection throughout the sailing season.