This subject comes up from time to time, thought I'd post a link to this article. Very informative.
http://strayvoltage.epri.com/protocols.asp
[the pool specific section is about 1/2 way down and titled "Measuring the Voltage Between Pool (or Hot Tub) Water and Ladder Steps or Handrail"]
http://strayvoltage.epri.com/protocols.asp
[the pool specific section is about 1/2 way down and titled "Measuring the Voltage Between Pool (or Hot Tub) Water and Ladder Steps or Handrail"]