How  to  prevent electrolysis corrosion, stray  current, paint bubbling, 97%  of  ALL  CAUSES via air or water,  in  3  SIMPLE  steps, permanently.

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Most need one SeaBis.


Galvanic causes 3% and is easily corrected when electrolysis is eliminated. We will advise you. 

Nearly 2,000 vessels cleared electrolysis corrosion.

Free training and diagnostic support.

COVID-19 response: If you cannot afford SeaBis we will do our best to assist you, free.

Battery, AC and shore power! We correct the cause. Completely and permanently. We succeed whereas a multi meter or half cell or reference or test lamp MUST fail.

Contacting us is free.  Waiting WILL cost you thousands $s.
Prevention is much cheaper than repairs. 

Contact us and we will step you thru preventing the CAUSE, with no thru hull penetration or moving parts or additional coating or additional anodes. Probably no Blocker or Isolating Transformer.

SeaBis 8 year guarantee and warranty. 20 year design life.


Find out how

How to prevent marine electrolysis corrosion


Stray current causes electrolysis corrosion.  That includes paint bubbling, boat or marina, rust, rig and process line corrosion. The SeaBis System prevents them all.



Corrosion is dependent on an electro-chemical reaction. Identify and correct the stray current and you will prevent 97% of all corrosion from occurring.


Prevent the CAUSE

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

Running man In a hurry?

Press Fast Track button. 
We will step you thru it.

*Most only need one SeaBis.* Video is of an extremely complex commercial yacht.  After a year use of SeaBis there are no paint bubbles! Read the reference. SEE the photo proof:
Save thousands $s – LISTEN – you have a friend.

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

Step 1: Identify

97% of  marine corrosion is caused by electrolysis. 3% by galvanic.

Marine electrolysis is ONLY caused by stray current.  It is the CAUSE of all the following:

Electrolysis dissolves metal

Paint bubbling. Marine electrolysis caused by stray current

Electrolysis corrodes propeller

Propeller corrosion caused by stray current creating electrolysis. Stainless steel forms worm holes.

Stray current corrosion

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

Electrolysis dissolves weld

Weld attracts stray current corrosion

Electrolysis dissolves the metal hull

Electrolysis dissolves the metal under the paint

Typical electrolysis white growth

Typical electrolysis white growth. 

How To Prevent Electrolysis Instructions with SeaBis System corrects the CAUSE.


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


Step 2: Understand

How to stop marine corrosion and electrolysis.

How to prevent the CAUSE electrolysis corrosion

How to prevent the CAUSE electrolysis corrosion

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

In conclusion the SeaBis System with SeaBis Instructions permanently prevents the CAUSE of stray current that creates marine corrosion by electrolysis.

Stray current explanation at: 
We will step you thru it.

Step 3: Eliminate

How to prevent electrolysis and corrosion:

First use SeaBis to measure  (stray) 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 prevent the CAUSE, follow SeaBis Instructions. Then our 8 year guarantee applies.

Galvanic is easily prevented when electrolysis – 97% is eliminated. We will step you through it.


Questions and answers:

Do you doubt corrosion is caused by stray current?

Wikipedia – proof: 

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 (1,000 grams) or two pound anode generates 1/(divided by)1,000,000 or one millionth of an amp protective current. Whereas stray current is 100 to at least 1,000,000 times stronger. Therefore you would need 100 too at least 10,000 kilo grams of anode! So use SeaBis Master System to prevent the CAUSE, completely and permanently.

Multi meter, half cell, reference electrode or test lamp?  Can any of them  prevent corrosion?

Sorry but no. The consequence will be to waste your time and money while corrosion escalates. The reason is corrosion is caused by CURRENT flow to the Earth. They will measure the COMBINED  VOLTAGE of every vessel within 200 meters and that of the Earth.  The result is misleading information.  Therefore use SeaBis Master System to measure current flow to the Earth and correct the cause –  it works 100%. That is why we provide a 8 year guarantee.

Why buy a Blocker?

Some will try confusion by calling Blocker a Galvanic Isolator!
A Blocker is wired into the mains earth.
Don’t be deceived. AC – Mains / shore power CAN NOT be the cause.

Ask for their WRITTEN guarantee. Read it.

SeaBis WRITTEN 8 year money back Guarantee at

SeaBis Guarantee, scroll down: 


AC or shore power cannot be the cause so what does the Blocker achieve?

AC is the abbreviation for Alternating Current.  It 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 is: DC has no  Counter Motive Force (Back EMF).

SeaBis Master will indicate DC in the AC.

Wikipedia – Counter Motive Force: 

  So do not blame the shore connection.  The SeaBis System will correct the cause.


How to prevent electrolysis and stray current:

First the ability of stray current to create marine electrolysis depends on causes in your vessel.  Also every other vessel within at least 180 meters.  In addition water depth less than 180 meters causes the Earth to increase stray current.

SeaBis measures the  TOTAL stray current affecting your vessel ONLY. Now use the SeaBis Master System to prevent the CAUSE of stray current, permanently. So preventing other vessels and the Earth from causing you electrolysis corrosion. Therefore preventing nearly all corrosion. Galvanic corrosion is only 3 % and easily prevented when the cause of electrolysis is corrected.

Rust cause:

Air carries stray current causing rust. Preventing stray current reduces rust. Use SeaBis!

More proof: 

Wikipedia explains the cause:  See

Wikipedia – Earth based current: 

– the Earth provides a current and electrical path that causes the stray current to increase.  In addition, both water and air are conductors. So they complete the circuit to the Earth.
Now correct the CAUSE: Use the SeaBis Master System to identify and PREVENT the cause.

Use and Technical explanation (easily understood)

SeaBis Master System prevents CAUSE of stray current – electrolysis.

Common names are rust, electrolysis, electrolytic action, marina corrosion, boat corrosion and galvanic. The CAUSE is always the same – stray current.  It is caused by faults in your vessel. The stray current causes corrosion by  marine electrolysis.  The solution is to use SeaBis Master System to Identify, understand, then prevent the cause, permanently.

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 all stray current CAUSE/s.  So saving you many thousands dollars.

  1. How to use SeaBis.
    Install SeaBis to battery positive, battery negative and metal hull or engine body. Switch off circuits until SeaBis indicates Normal (green). The last circuit switched off was the cause. It now has no power so is easily identified. SeaBis System contains full instructions. Support is included. Any difficulties then please contact me.
  2. What is electrolysis corrosion?
    Electric (stray) current flowing from your vessel to the Earth (we stand on) carrying your metal.
  3. What is galvanic corrosion?
    When dissimilar metals are in a conductor such as water a current flows between them dissolving the metal. Easily prevented when electrolysis is prevented. Anodes, when stray current corrosion is eliminated, will prevent galvanic and should last 3 to 4 years.  If they do not then stray current is the cause. It is commonly vastly accelerated by electrolysis. 
  4. What is rust?
    Rust is simply air carried current often vastly accelerated by stray current – electrolysis.
  5. What is the solution?
    This is where SeaBis pays for itself, very quickly.  SeaBis Master System prevents the 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. Old household wire was the leading cause.  It was originally installed by Beneteau and new electronics that had not been earthed correctly. 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 SeaBis Instructions 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