January 2020 (ROTM#133) Bondi Beach, Sydney, Australia

This is an image of Bondi Beach taken on Christmas Day 2019 courtesy of the AAP. Christmas Day is always a major challenge for the Bondi Lifeguards because the beach is packed with people who may not be in the best condition when they enter the water. Keeping everyone safe is a nightmare, particularly when there are rip currents, which are almost always present along the beach. 

 The most prominent rip current in this picture is the narrow channel of darker water extending out from the middle of the beach. The lifeguards have done a good job of keeping people out of it. Except the surfer who is using it to paddle out. The interesting thing about this picture is that it's taken at low tide, when you could probably stand up in the rip current channel without too much trouble. As the tide starts to come in though, more waves will break across the shallow sandbars and the rip will start to flow faster until at high tide, the rip will likely slow down as the water depths are too deep to promote much wave breaking.

 The important lesson here is that rip current behaviour is very much influenced by the tide. Most rips tend to flow faster several hours either side of low tide and slower around high tide, where they may even stop flowing altogether. It's a good reason to pay attention to what the tides are doing on any surf beach that you may visit.