Hello Meril,
It turns out that the danger of death from electrical shock is related to the amount current passing through the body. Since the current is proportional to the voltage divided by the circuit resistance you have to consider all of the parameters. If you have wet, salty hands and grab hold of the terminals of a 12 Volt battery, there is a significant danger of severe shock or even death in certain cases. I suspect that in an overturned canoe one wouldn't do that.
LeeH
(published on 03/11/2014)