How to stop marine corrosion, stray current, electrolysis CAUSE in 3 steps, permanently.

Battery, AC and shore power! We correct the cause. Completely and permanently.

No thru hull penetration or moving parts or additional coating or additional anodes.

8 year guarantee. 20 year design life.


Find out how

How to prevent marine corrosion and electrolysis


Stray current causes corrosion.  That includes boat or marina, rust, rig and process line corrosion. It does so by electrolysis. The SeaBis System controls them all.



Corrosion is dependent on an electro-chemical reaction. Identify and correct the stray current and you will prevent ALL corrosion from occurring.



SeaBis Master System correctly identifies the CAUSE of stray current corrosion – electrolysis and corrects that cause, saving you thousands of dollars in maintenance and repair.

How to prevent marine corrosion and electrolysis

Video from SeaBis at work! An extremely complex commercial yacht-most only need one SeaBis.  After a year use of SeaBis there are no paint bubbles! Detail: seabis-reference

How to prevent marine corrosion and electrolysis CAUSE in 3 steps, permanently.

Step 1: Identify

Stray Current Corrosion

Stray current dissolves your metal

Stray current dissolves your metal so lifts paint

Electrolysis corrodes propeller

Propeller corrosion caused by electrolysis. Stainless steel forms worm holes.


Stray current corrosion

Electrolysis created by stray current corrosion to engine leg in 14 days


Electrolysis dissolves the metal under the paint


Typical electrolysis white growth.  CAUSE is prevented by SeaBis System.


Marine corrosion is caused by stray current.  I witness that stray current destroy propellers and hulls in 10 days, many times every year.  Wiring or equipment defects on board your vessel cause the stray current. The stray current flows from your vessel to the Earth.  SeaBis Master System pays for itself, very quickly, eliminating the stray current cause.  So saving you many thousands dollars.

Do you doubt corrosion is caused by stray current?

Then see Wikipedia, electrolysis. You will see the Wikipedia apparatus power is red and black – so must be Direct Current (DC or battery current). Wikipedia text clearly states DC current. Wikipedia does not state Alternating Current (AC or inverter or mains or shore power). So shore power or AC cannot be the cause.

Anodes?  Can I add more to prevent corrosion:

A one kilo gram or two pound anode generates one millionth of an amp protective current.  Whereas stray current is thousands or whole amps.  So stray current is at least a thousand times stronger.  Therefore you would need at least 1,000 kilo grams of anode! Now use SeaBis Master System to prevent the CAUSE, completely and permanently.

Reference electrode?  Can it, with my multi meter  prevent corrosion?

Sorry but no. You will waste your time and money. The Reference electrode will measure the COMBINED  VOLTAGE of every vessel within 200 meters and that of the Earth.  Use SeaBis Master System –  it works 100%.

Stray current accelerates corrosion:

First the corrosive ability of marine electrolysis depends on causes in your boat.  Second every other boat within at least 180 meters.  In addition shallow water causes the Earth to have a increased affect. SeaBis measures the  TOTAL stray current affecting your boat ONLY. SeaBis Master System prevents the CAUSE of stray current, permanently. So prevents nearly all corrosion.

Your metal contacts moisture:

The moisture creates an electrical circuit to the Earth. Now when you connect a battery it vastly accelerates stray current.  So creating corrosion by marine electrolysis. Often this  is termed boat or marina corrosion or rust.

AC or shore power cannot be the cause:

AC is the abbreviation for Alternating Current.  AC reverses direction every half Cycle or Hertz.  So IF a particle is removed in the first half Cycle it will be replaced in second half Cycle . Therefore AC cannot cause electrolysis.  In addition, if there were DC in AC then every AC appliance would burn out in a few seconds. The reason: DC has no  Counter Motive Force (Back EMF).  So do not blame the shore connection.  The SeaBis System will prevent DC in AC.

Rust cause:

Air carries stray current causing marine electrolysis. Therefore creates rust. Preventing stray current reduces rust. Use SeaBis!

More proof: 

Wikipedia explains the source:  See Wikipedia, Earth based current – the Earth provides a current and electrical path so causing the stray current to increase.  Water and air are conductors. So they complete the circuit to the Earth.
To correct the CAUSE: Use the SeaBis Master System to identify and PREVENT the cause.

Step 2: Understand

How to prevent marine corrosion and electrolysis.
SeaBis stops CAUSE of stray current

Stray current – electrolytic corrosion CAUSE eliminated

Most importantly stray current is dependent on ALL of 3 inputs: moisture, metal and an electrical (stray) current.  So elimination of stray current prevents corrosion.

In conclusion the SeaBis System with How To Stop Corrosion permanently prevents the CAUSE of stray current that creates marine corrosion by electrolysis.

Current explanation at How page.

Step 3: Eliminate

To complete repair:

First use SeaBis to measure current flow to the Earth.  Observing the lights on SeaBis. Second, identify the circuit causing stray current by switching off circuits until SeaBis Master indicates Normal (green).  The last circuit you switched off was the cause.  Finally stop the CAUSE, follow How To Stop Corrosion. Then our 8 year guarantee applies.

Link to How to conquer corrosion in 3 steps

Link to Self paced Training Course

Proof we are correct Wikipedia

Technical explanation (easily understood)

SeaBis Master System stops the CAUSE of stray current – electrolysis.

Common names are rust, electrolysis, electrolytic action, marina corrosion, boat corrosion and galvanic. The CAUSE is always the same-marine electrolysis caused by faults on your boat.  The solution is to use SeaBis Master System to Identify, understand, then eliminate the cause, permanently.

Rust is simply air carried current often vastly accelerated by stray current – electrolysis.

Galvanic is vastly accelerated by electrolysis.  Galvanic is the minority cause of two different metals being in proximity in a conductor such as water.  Galvanic is a million times slower than stray current corrosion – electrolysis.  Anodes, when stray current corrosion is eliminated, will stop galvanic and should last 3 to 4 years.  If they do not then stray current is the cause.

Marine electrolysis is caused by stray current flowing from your vessel to the Earth.  This is where SeaBis pays for itself, very quickly.  SeaBis Master System eliminates stray current CAUSE.  So saving you many thousands dollars.


The SeaBis box proved very useful in tracking down multiple stray current problems aboard our boat. The leading cause was old household wire originally installed by Beneteau and new electronics that had not been earthed correctly. The service from SeaBis was excellent with prompt replies to my queries. I did really appreciate your help. Thanks again for your help, its been A1 service.

Andrew Deeley / SV Utopia II

Marine electrolysis that causes marine corrosion eliminated

Hi Glen, Thanks for your help earlier today. I’ve easily isolated the offending components… spreader lights depth sounder …and the starter motor. I guess the latter is due to carbon build up as it is meant to be a separate earth unit. Anyhow, back on track now. Cheers, Mike

Mike Brady

Marine electrolysis that causes marine corrosion eliminated

My wife and I are currently circumnavigating aboard our 45 ft. steel yacht. I purchased a SeaBis System after borrowing a friend’s SeaBis and discovering that I, too, had stray current – a flashing red critical light is hard to ignore. This was after the boat had been tested and cleared by the test bulb method. I have no electrical skills but, by following the system, I was able to detect and eliminate the four causes of stray current – a non-isolated genset, a VHF aerial not insulated from the mast, a fuel tank gauge not insulated from the SS day tank, and the connection between a non 12v computer and the SSB radio – to achieve a very satisfying green normal light.

Furthermore, the SeaBis has identified AC leakage from worn brushes in 12v fans and, most recently, a path between the brushes and case on my Balmar alternator, which blew the SeaBis fuse before causing any damage. I consider the SeaBis to be a vital element in diagnosing my yacht’s electrical health. I would also add that Glen has been a great guy to deal with, standing behind his product and providing a wealth of diagnostic advice.

You may use my testimonial with verification.

Mark and Heather Domney

Marine electrolysis that causes marine corrosion eliminated

Six years ago I purchased a Dutch barge in Amsterdam, shipped it to the UK and spent four years restoring it to a fully functioning residential boat in my spare time. During this process I learnt much about the ways of vessels which has added to my automobile knowledge. One of the things I learnt was that corrosion was destroying my hull which lead into an investigation, this in turn lead me to the SeaBis. I completed How To Stop Corrosion and time has proven the cause is removed. No more stray current corrosion.

Paul Michelmore

Marine electrolysis that causes marine corrosion eliminated

Well Glen your SeaBis system fixed the cause. No problems in 5 months. It was a deck generator and CB radio.

John Singleton

Marine electrolysis that causes marine corrosion eliminated

We purchased a steel cruiser 8 years ago and had problems not long after purchase with corrosion on the decks. When the boat was slipped we had evidence of metal corrosion which I think is caused by electrolysis, on the hull as well. When the boat was returned to the water I had a marine electrician check out the boat and he said that our boat was OK and the corrosion was caused by the boat next to us in the marina.

We then believed that was the cause, we tried to get the marina to do something about it but they did not want to know. When the boat was slipped 18 months later the corrosion was that bad we had to sand blast back to bare metal and repaint including the decks. We moved the boat out of marina and put it on a swing mooring, when the boat was slipped again it was evident again. I looked on the web and found the SeaBis site and purchased a unit since then the decks have stopped showing signs of accelerated corrosion. Although we have yet to slip the boat again to check the hull I am confident that the SeaBis unit is performing, as the decks are looking great.

Michael Cuthbert

 Two Volvo engines with a carbon fibre mast and extensive advanced corrosion to engines. One has previously been replaced. The Owner and Peter traced the cause to a separate power supply in the instrumentation. Fitted an isolating diode and isolating switches to both engines. Problem fixed.

Peter – Qualified and experienced Marine Electrician