November 2021 (ROTM#155) Coledale Beach, Northern Illawarra, NSW Australia

Apologies if there’s a bit of ‘sameness’ to the Rip of the Months the last few years, but in these COVID lockdown times, travel has been limited so most of these pictures tend to be from my local beaches. But these beaches are the rip gift that keeps on giving – there are almost always rips of every type!

Here’s another boundary rip, sometimes called a permanent or structural rip, that is flowing offshore against the rock platform.  You can see the green gap pretty clearly. It’s narrow, only a few m’s wide and it hugs the rock platform and would take you around the corner out of sight.

Now there’s two reasons why rips almost always form against headlands and rock platforms and it doesn’t matter what direction the waves are coming from: 1. If the waves in this picture were coming from the south (i.e. approaching from the top right), they would create a longshore drift that would hit the rocks (the boundary) and be deflected offshore. That’s easy to understand; and 2. If the waves were coming from the north (i.e. approaching from top left), more waves would break in the middle of the beach due to protection from the headland/rocks. That causes the water level to build up in the middle of the beach and start flowing sideways to where the waves aren’t breaking as much (and the water levels are lower) – which is against the rocks! Water flows ‘downhill’ right? So when it comes to boundary rips, it’s a double whammy.

Coledale is a nice beach and actually has a public campground, but it almost always has rips in each corner and often one in the middle of the beach as well. Fortunately it’s patrolled by Wollongong City Council lifeguards and volunteer lifesavers in the summer.

White is nice, green is mean! I can’t emphasise that enough.