Rust Seeker Electrolysis Detector

Silver Silver Chloride Half Cell with 15 Metre Cable

WE NOW SUPPLY ONLY THE 15 METRE RUSTSEEKER. (This was by far the most popular product.)


Plug this probe into into your multi meter for precise electrolysis testing of a boat's bonding system and zinc effectiveness.  

This is a simple and effective testing solution that will quickly determine if a component such as props, shafts or underwater fittings are being  protected by the anode.  Or if your bonding wires need attention.

Every boat should have one of these test units.

Rust Seeker™ is a silver/silver chloride reference electrode. It measures the electrochemical potential of your vessel, indicating whether your vessel is adequately protected against corrosion.

Using Rust Seeker™ and most standard multimeters you can take readings around your vessel, and then compare the results against the assessment table to check if your vessel is protected against corrosion.

How does it work?

Rust Seeker™ is an electrochemical cell which has a stable and reproducible potential so it can be used as a reference point for voltage measurements. Rust Seeker™ consists of a silver wire, coated with a layer of silver chloride, which is saturated in a potassium chloride gel.

The porous plug allows contact with the seawater which allows Rust Seeker™ to consistently produce accurate electrochemical potential readings of your vessel.

Where can I use Rust Seeker™?

Rust Seeker™ is designed for use in clean seawater. It is designed to be used on aluminium and steel hulled vessels. Rust Seeker™ can also be used in freshwater.

Is my multimeter suitable?
Rust Seeker™ works with most commonly available digital or analogue multimeters. For the most accurate readings the multimeter requires an input impedance of at least 10MΩ (megohms) and an accuracy of +/-10mV (millivolts) or better.

Use Rust Seeker™ to identify stray current
Whether your vessel is made of aluminium, fibrebreglass, steel or timber, Rust Seeker™ can be used to idetify stray current.

Your hull does not necessarily need to be metallic to suffer from the effects of electrolytic corrosion. Sub surface metallic components such as propellers, shafts and shaft struts, rudder blades and skin fittings are also at risk.

Permanently moored vessels can be susceptible to 4 main sources of stray current.

- Marina mains power or from marina cathodic protection system
- Ship onboard power
- Neighbouring moored vessels
- Submarine power cables (very rare and signage almost always present to identify cable location)

When galvanic anodes have been correctly designed and installed, the electrical potential of the vessel and its individual components should be in the range of -800mV to - 1,100mV in sea water (with respect to a AgAgCl Reference Electrode).

If stray current is having an adverse effect on your vessel, Rust Seeker™ will detect a shift in your vessel’s potential to a more positive reading.

This can be interpreted in one of two ways:

- Loss of or spent galvanic anodes possibly combined with poor coating system.
- Electrolytic corrosion through stray current.


Two Sizes:

The Rust Seeker™ reference electrode is available as a standard 15m product.  We found 15m was by far the most popular length chosen by customers.

RS-15 (15 metres of Cable)
For testing vessels or structures where the distance between the deck and the test area is 15m or less.  

RS-30 (30 metres of Cable)  SPECIAL ORDER
For testing large vessels or structures where the distance between the deck and the test area is 30m or less.   

Each Rust Seeker is supplied with:

  • a heavy-duty neoprene bag
  • a heavy duty water proof booklet which includes instructions and space for recording results. 
  • a velcro strap for safely suspending Rust Seeker in the water.
  • an extra rubber cap, just in case you lose one.



SKU rustseek