Cape Town - The National Sea Rescue Institute (NSRI) has warned tourists and locals to be weary of extreme sea conditions in the Western Cape this summer. An Eyewitness News update reports that at least three drowning incidents apparently caused by rip currents, have occurred over the past week. The NSRI confirmed that it is expecting strong rip currents along the west coast this week and has urged all beachgoers to exercise extreme caution, as higher than normal high-tide, lower than normal low-tide, and rip currents are going to be their strongest.The NSRI's Craig Lambinon suggested going to beaches where and when lifeguards are on duty and obeying the instructions of the lifeguards. Swim in the safety swimming zones that the lifeguards post using yellow flags.NSRI volunteer and winner of the 2012 Centrum Guardian project, Torsten Henshel, narrates a sea rescue video that explains what a rip current looks like, how you can avoid one, what you can do if you get caught in one, and what to do if you see someone else in difficulty, in: Break the Grip of the Rip. Break the Grip of The Rip® from Sea Rescue on Vimeo.Keep up to date with what's happening at the sea, Follow https://twitter.com/nsri NSRI on twitter.