i got dunked one time and was held under water just a little bit longer than i was comfortable with. there was a lot of energy out there--especially on the closeouts. all things considered, though, the paddle-out wasn't bad and general conditions were a lot saner than i expected.
of course, josh, you need not worry because ice floats!
undertow: any strong current below the surface of a body of water, moving in a direction different from that of the surface current.
rip current: A strong, narrow surface current that flows rapidly away from the shore. Rip currents form when excess water that has accumulated along a shore due to wind and waves rushes back suddenly to deeper waters. Also called rip tide.
The definitions are synonymous. They both pull you away from where you want to be or in the case of surfing they help you get out to the lineup quicker.
I was caught in a big rip current last night. Before I could even react to it it had pulled me out 30 yards or more. I'm glad I was on a board.
I don't care what you call it. The only important thing is do you know how to get out of it?
the local (delmarva) weatherman makes a huge fuss about rip currents--like they are a harbinger of the apocalypse or something. as a surfer, a rip can be a good thing. getting held under pretty much sucks and makes one a little bit tentative about catching that next wave.