Fulmini e lampi....

[IanSolo]

La norma sopracitata sull'argomento dice (faccio uno strappo alla regola e ne riporto una parte):

5.9 Lightning ground
5.9.1 A lightning ground for a craft shall consist of any metal surface which is submerged in the water, in
any conditions of heel or trim, having an area of at least 0,1 m 2. It shall consist of at least one of the following:
a) an external ground plate or equivalent, located as close to the base of the lightning-protective mast as
practicable to minimize any horizontal runs in the lightning grounding conductor;
b) an external grounding strip of copper, copper alloy, stainless steel or aluminum having a minimum
thickness of 5 mm and a minimum width of 19 mm.
The edges of the external ground plate or grounding strip should be sharp, exposed and not caulked or faired
into the adjoining area.
NOTE A grounding strip approximately 20 mm wide and 4 m long has a substantially greater edge area exposed to
the water which, compared to a ground plate, will improve the dissipation of charges.
5.9.2 The grounding strip, if used, shall extend from a point as close to the base of the lightning-protective
mast as practicable towards the aft end of the craft where a direct connection to the craft's engine can be
made.
5.9.3 Metallic rudder surfaces, struts, metal centreboards and keels, or the ground plate for radio
transmitters, may be used for the external ground plate if they meet the surface area and location
requirements of 5.9.1 a).
5.9.4 A metal hull itself constitutes an adequate lightning ground plate.