Thanks everyone for the nice comments about the image I posted with my question. Glad you like it.
Using a GFI circuit isn't really going to work because most of the locations I've seen with pools make a point of NOT having any outlets there to begin with, obviously as a safety precaution.
And obviously a Porty can't be plugged in anyway. So even that's dangerous (as would be a Vivitar 283 as was pointed out).
Ok, I might still use my Porty in such a situation, but only if the floor area was dry and there was no danger at all of a head falling into the water. But I accept that it's somewhat dangerous.
And that brings me to another question about this...
We often see photos (Rolando does this often) of models in the water at the edge of a beach and if I'm not mistaken recently there was even a behind-the-scenes photo of an assistant with Porty pack over his shoulder and a head supported on a monopod with him standing in the water near the model. We're not talking about a bathtub here or even a swimming pool... is the danger the same if that fellow stumbles and the head falls into the ocean say within 10 feet of the model (and even closer to himself)? Surely salt water is even more dangerous than fresh in terms of conducting electricity?
And yet another question: I've been planning on doing a fashion shoot at night in a downtown area with brightly lit neon signs behind the model. But I wanted the street wet (like after a rainstorm) to give even more reflections. I was planning on dragging the shutter to pick up the ambience and using my Porty and head to light up the model. Does this pose any hazard? What if it's drizzling or raining harder?
I'm glad I asked about this, and grateful for all the replies, as there is obviously danger associated with this and we should all be aware of it and do what we can to keep everyone safe.
Anyway, since some of you liked that photo, here's another from the same session: