As a simple experiment, just use a 12 VAC filament transformer (do they
still call them that?) and measure the current from one prop to the next
with the other wire clipped to the green grounding conductor. It's tough
to measure DC resistance in water because the surface areas of the
conductors get drawn into the act and the current tends to polarize the
path at the electrodes. But the 12 VAC route gives you exactly what you
would get with at 120 volts with no risk.

On breaker tripping, there've been an awful lot of power tools
(connected and running) dropped into sal****er that never tripped their
breakers. Extension cords (hot) are found hanging in the water routinely
at some marinas. So by all means give it a test. But please just use 12
VAC and measure the current. We can just multiply by ten to get the 120
VAC current.

I'm with you 100% on isolation from galvanic currents.

Turns out that the lethal situation for swimmers in the presence of
these strong fields is far worse in fresh water than in sal****er,
contrary to one's initial expectation. In sal****er, the current is so
overwhelmed with little high-conductivity paths around the swimmer that
virtually no current passes thru the swimmer.

In fresh water, the swimmer looks like a low resistance "short" in the
middle of the field (he bends the field, actually) and concentrates the
current through himself!

Keep us posted on results.

Chuck