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Mobile lightning protection
A cost-effective mobile lightning protection system, which is
frequently used for occasional charters of a yacht, can be easily
implemented. To this end, the lower part of the aluminium
mast is fitted with a ball pin, which is used as down conductor.
A lightning current carrying terminal, which is connected to
two other terminals and two braided copper strips of several
metres, is screwed to the ball pin. The terminals are connected
to the upper shrouds to use them as down conductor. The free
ends of both braided copper strips must be immersed at least
1.5 m in the water (Figure 9.34.3).
All components and the relevant connections must be capable
of carrying lightning currents and must be corrosion-proof.
This protection measure can be quickly implemented when
a thunderstorm approaches and provides a certain protection
against lightning strikes. It is not entirely clear to what
extent mobile lightning protection systems provide protection
for yachts since the normative requirements for equipotential
bonding (personal protection), separation distances, etc. are
not observed. It can only be assumed that lightning damage
such as punctures of the body can be prevented since most of
the lightning current flows through the braided copper strips
into the water. Therefore, a fixed lightning protection system
always has to be preferred.[b]

The earth plate must have
a surface of at least 0.25 m2 and must be made of copper

The copper
connecting conductors must have a minimum cross-section of
16 mm2