Examining rip current escape strategies in non-traditional beach morphologies

2016 
Rip currents are a significant hazard on global surf beaches and are a factor in hundreds of drowning fatalities each year. Contemporary rip current safety information often idealises rip currents as part of a Transverse Bar Rip (TBR) morphology with rip channels bound by shallow, shore-connected bars. Real-world conditions frequently differ from this model, with potential implications for rip current escape strategies promoted to, and undertaken by, the general public. This study describes outcomes of rip current escape strategies conducted at North Cronulla Beach, NSW, Australia, over two distinct morphologies; a mixed Low Tide Terrace/Transverse Bar Rip (LTT/TBR) and a Rhythmic Bar Beach (RBB) system lacking shore-connected bars. Swimmers attempted to escape by adopting one of three pre-determined strategies: Stay Afloat, Swim Parallel and Swim Onshore. A total of 100 escape attempts were conducted, with the RBB system experiencing longer duration ( $$\bar{t}$$ t ¯ = 2.4 min) escapes than the LTT system ( $$\bar{t}$$ t ¯ = 0.8 min). The RBB system was associated with a higher rate of action failure, particularly for Stay Afloat, due to a lack of shore connectivity of adjacent bars. Swim Parallel was of lower duration ( $$\bar{t}$$ t ¯ RIP1 = 0.66, $$\bar{t}$$ t ¯ RIP2 = 2.68 min) in both systems, but durations and distances to safety in the RBB system often exceeded swimming abilities of weaker bathers. Although Swim Onshore was more successful ( $$\bar{t}$$ t ¯ RIP1 = 0.22, $$\bar{t}$$ t ¯ RIP2 = 1.65 min) than Swim Parallel, promotion of such a strategy is strongly discouraged in conventional safety advice. Results suggest that contemporary rip current escape strategies may be inappropriate in non-TBR rip current systems and that alternative strategies should be considered, including Swim Onshore and a greater focus on preventative strategies, particularly in relation to bathers with limited swimming ability. Copyright Springer Science+Business Media Dordrecht 2016
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