1. electron ( - -) flow Fe2+ 2OH->> Fe(OH)2 2H+ + 2OH- + 2 electrons >> H2 + 2OH- +++++++ - - - - Steel hull without anode leading to galvanic corrosion bronze fitting Fe3+/Fe2+ ion flow (+++) ion flow (- - - )

2. electron ( - -) flow 2H+ + 2OH- + 2 electrons >> H2 + 2OH- - - - - ANODE +++++++ Steel hull with Zn anode closed loop but no corrosion because of protecting anode ion flow (- - -) Zn2+ Zn2+ 2OH->> Zn(OH)2 ion flow (- - -)

3. electrons flow not possible through polyester no charges separation possible >>> no galvanic corrosion e.g. steel keel bronze fitting Polyester hull without anode no closed loop > no corrosion

4. electrons flow through connecting wires e.g. steel keel bronze fitting Polyester hull with anode connected to skin fitting and keel closed loop but no corrosion because of protecting anode ANODE + + + + + Zn2+ Zn2+ 2OH->> Zn(OH)2 ion flow (- - -) - - - - - 2H+ + 2OH- + 2 electrons >> H2 + 2OH- - 2H+ + 2OH- + 2 electrons >> H2 + 2OH-