My best guess would be that there are too many variables to say one way or another. Most of the published material on human shocks is based on C F Dalziel’s work in the middle of last century.
Water conductivity is most greatly affected by mineral content. This can be demonstrated to oneself with a bowl of water, a salt shaker and an ohmmeter.
The path of current and resultant voltage gradients at any given moment are predictable under very controlled conditions, but in real life, can change rapidly in an accident situation. For simplicity’s sake, consider two wires in an insulated container of water. The electric potential at any two points can change radically with moving the two energized conductor positions, and the points of contact to a human body part immersed in the water.
It is important to realize that current through a body part will significantly increase if the skin is wet. That is one reason why conductive objects in the vicinity of swimming pools, even through “non-electric,” are mandated to be bonded together to limit even very small potential differences between them.
Two miscellaneous online references are..
www.schneider-electric.com/en/pdf/ect114.pdf www.dep.state.pa.us/dep/deputate/minres/dms/website/electrical/Bob's%20electrical%20program.ppt
