Some history on "Why do we have non-conductive tiller extensions in North America?"
In the beginning . . . all Hobies had aluminum tiller extensions. They were OK, but they bent easily, and if bent too far or too many times, they broke. Guaranteed there is not a straight one in existence today.
In the Jan/Feb 1979 HOTLINE, Hobie Cat Co. announced a free tiller extension replacement offer - aluminum tiller extensions would be replaced with the white fiberglass, non-conductive extensions we are all familiar with today. The article mentioned that all new boats, starting with November 1978 production, would come equipped with the non-conductive tillers as standard equipment. The article stated:
Jan/Feb 1979 Hobie HOTLINE wrote:
Our engineering investigations have established one possible deterrent [to power line electrocution] which we feel should be pursued. In a limited number of power line incidents, an added measure of safety can result when a white non-electrical conducting tiller extension is used by the skipper.
The free tiller extension replacement offer, originally set to expire on April 30, 1979 was extended to June 30, 1979.
The new tiller extensions were much more durable than the aluminum ones. They could bend and flex (to a certain degree) and remain straight and undamaged.
In May/Jun 1979 issue of the HOTLINE, there were class rule amendments for the Hobie 18 which included the statement "IT IS RECOMMENDED THAT THE TILLER BE MADE OF A NON-ELECTRICAL CONDUCTIVE MATERIAL" (all caps in the original).
In the 1982 edition of the World Hobie Class Association Racing Rules, Rule 11.1 stated (in part):
THE TILLER EXTENSION SHALL BE MADE OF A NON-ELECTRICAL CONDUCTIVE MATERIAL ON ALL NORTH AMERICAN REGION BOATS EFFECTIVE JUNE 1, 1982. THE NON-ELECTRICAL CONDUCTIVE TILLER EXTENSION IS RECOMMENDED ON ALL BOATS WORLDWIDE.
(all caps in the original)
That language has survived (including the all caps, but less the deadline date) in the International Hobie Class Association Class Rules to this day.
Speculation (my own) is that the replacement offer was the result of a litigation settlement, very much like the Comptip that followed a few years later. Only the old-timers at Hobie Cat (Bill Baldwin and maybe Hugh Greenwald) will know for sure.
Some question "Why the tiller extension?" When the mast contacts a power line, the current will seek the easiest path to ground (the water). The pylons are insulated by the hull structure. The path would then be through the tramp frame, through the person holding the tiller extension, to the rudder castings. If the tiller is non-conductive, it breaks that path. That assumes that the boat is relatively static in the water (pylons not immersed).
In reality, everything is wet - often with salt water (a conductive electrolyte) and in all likelihood, everything on the tramp frame would be energized.