I knew someone will say about floor contact but I believe people sane enough not to touch main power staying in a salty water. I told one hand method it safer not total safe, but chance of dying reduce greatly so why not to use this opportunity.
The only safe way to work around anything above 40 volts is to follow lock out / tag out procedures.

I am the operations manager for a large chemical company and electricity is but one of the many hazards my crew and myself have to contend with. We have set safety standards so that everyone goes home to their family at the end of the day.

You check as many times as needed to make sure the system is "dead" and that there is no way the system can become "live". This goes for computers that control the systems also. Do you really want to put your life in the hands of a faulty relay?

There is ABSOLUTELY no reason to work on a "live" system.

I have heard the "one hand method" more times than I care to count. When I do hear it the person who said it is off the job.

Ma'am, I am sorry to tell you this... you husband is dead. It could have been worse though. He could have been using both hands.