Watch the video's on this site, particularly the video's which you find under this title. And you will realize, despite all diagrams and pictures you've studied on rip currents,  how difficult it is to recognize the real thing.

"Pictures of rips are great educational tools and certainly better than diagrams, but nothing beats the real thing. These are 3 short videos of the same rip at Stanwell Park, NSW, Australia taken over a period of about 2 months from different angles. The rip is channelised, but just watch and observe...it's more than just looking for dark gaps. The water of the seaward flowing rip has a distinctly different texture, it's choppy...and it's moving! Even though waves are coming in, it's moving out against them. They really are like rivers of the sea."

http://www.scienceofthesurf.com/ripom.html