Like Mike Hickey said get a PocketWizard or a Wein safe sync.
This outdoor shot was made possible with the PocketWizard's.
Without the PocketWizard I would have had a 20 / 30 foot cable to trip over. At any given time on this shoot there were four or five people around. And with water involved WELL YOU KNOW.
Its bad enough if the camera gets fried. But if you or a model gets fried.
Don't think it cant happen. A friend of mine David Slaughter was almost killed by a bad power pack that shorted out. Without water around inside in a studio. And no he's not stupid. He's a rocket scientist (not kidding here) David S. was also a teacher at Brooks Institute in SB.