Darlene owner of "The
Mermaid Lounge" reported on her
own blog that her propellers had suffered from severe corrosion.
I suggested that 'stray current corrosion' might be the
culprit as the extent of the damage appeared, from the photos, to be
Those 'stray currents' can be generated either
externally or internally.
The external sources can be faulty shore power
connections or leaks from other boats nearby.
While there are regulations and inspections covering
marina and boat yard installations it is rare that either your or your
neighbour's boats will be checked.
As boats get bigger, electrical systems get more
complicated and add to that
the extra 'toys' that are added on a DIY
and the chances of error are compounded.
The usual errors include, poor groundings, reversed
polarities, the mixing of AC and DC wiring, etc.
Loosing you propeller may seem bad enough but what about
your or your love one's lives?
'Electric Shock Drowning' (ESD) can get you right at the
marina, in the most shocking way.
Most boaters are not aware that such a danger even
The amount of electricity entering the body can be so
small (as low 10 milliamps) that often the post-mortem doesn’t catch
that stray current was the cause of death.
The problem is that muscles exposed to charged
can become paralyzed, making it impossible to swim or even breathe.
Drowning happens just that much faster since obviously
you can’t do anything to aid yourself.
Stray current can be prevented through the
use of a Galvanic
None of the rules, standards, recommended practices,
will be much consolation for anyone whose muscular system is shocked
into paralysis simply for reaching into the water to retrieve something.
And the boater is rarely protected from himself or
by required inspections.
You just have to be committed to doing the work
licensed and experienced help if necessary.