October 2020 (ROTM#142) Towyn Beach, Cornwall, UK

One of the most common types of rip currents are boundary rip currents which flow next to physical structures such as headlands, rock platforms, groynes, jetties and piers. How they form is fairly easy to understand. Basically when water flows along the beach and hits the boundary, it is deflected offshore. Often boundary rips are almost permanent features meaning that they are almost always there and always flowing offshore.

For this reason, it's extremely dangerous to swim near any type of physical structure and the Great Lakes in the US and Canada have big problems with people drowning in rips near piers and groynes. For some reason I don't have too many good pictures of boundary rip currents flowing along groynes so I was pleased to come across the following video by Jay Cooper. 

He's at Towyn Beach in Cornwall in the UK and does an amazing job of talking about rip currents and then jumps in the boundary rip and takes you through the process of getting out of it. It's amazing how the rip starts off slowly, but suddenly increases in speed and before you know it, he's well offshore. But he calmly floats and then slowly swims to the side until he can stand up on the shallow sandbar. It's such a great video...well done Jay!

This picture is a screenshot from the video from the perspective as if you were standing on the beach. There are darker gaps of deeper water where the waves aren't breaking as much on both sides of the groyne. Those are the rips and it's a double whammy - so please don't swim anywhere near structures when you go to the beach.

Screenshot from a remarkable video