February 2013 (ROTM#50) Bulli Beach, NSW Australia

We've just finished another field experiment to measure how rip currents behave and how swimmers can escape them. To measure rip current flow patterns and speeds, we placed over 30 of these pvc 'drifters' with GPS attached into the rip. Some of the results are so surprising. I'll post them eventually, but there's a lot going on in the surf zone that is completely hidden from the naked eye. It's certainly not textbook stuff that rips just take water offshore! The dye release in the background shows that not all rips flow offshore, some flow at strong angles to the beach.

Our experiment at Bulli Beach, just north of Wollongong, NSW was the last of 6 experiments we've done over the last 15 months. We've learned a lot about rips, but also raised a lot of questions. One thing is for sure...there is no single message or action that you should take when you get caught in a rip. Rip flow is incredibly variable and the best action is not to get caught in them in the first place. Swim where lifeguards can see you! Thanks to Barbara Brighton for the pic.

Drifters + dye = rip experiment