OPINION: Tahunanui Beach is often promoted as being among the safest in New Zealand, and mostly it is.
Complacency and water are never a good fit, however, and the line between fun and disaster can be fine. As a Stoke family discovered on Sunday, the Blind Channel at Tahunanui's Back Beach can be challenging for all but the strongest of swimmers. When the tide is right - or rather, wrong - strong rips and currents can form.
Unlike the gently sloping and generally benign main beach, the channel also drops away quickly and swimmers can be out of their depth within a metre or two from the shore. This can have its own appeal, especially at low tide when front beach users must wade a long way to reach waist-height water.
However, local knowledge of the rips and currents, and the belief that rays and small sharks tend to be found there, keep down the numbers using the channel other than for fishing and kite-boarding.
The Clark family escaped an encounter with the beach's strong currents on Sunday without harm - but say if not for a "mystery hero" it could have ended in disaster. Aidan, 11, got stuck in a rip and his father Anthony plunged in to assist his son but made little headway. A stranger joined in and was a strong-enough swimmer to pull the boy clear, freeing Mr Clark to drag himself back to shore.
Life is full of what-ifs, and there is little point in reflecting on how it might have ended without this intervention. However, in sharing their story they have done others a favour in reminding people of the risks associated with water in general, and particularly this part of a popular beach.
Every summer there are mini-dramas at beaches around the region: whether caused by foolishness, inexperience, equipment failure or just bad luck.
Usually they end well, although rescue authorities must get heartily fed up with gung-ho types getting themselves into trouble by failing to take advice or commonsense precautions. The Clark family do not fit this category at all. However, their experience has also highlighted the fact that signs warning of the dangers in swimming at the Back Beach in some conditions have been removed. It would do no harm to replace them, both at Parkers Cove and the other popular Back Beach car parks.
The front beach, meanwhile, might seem tame by comparison but it is patrolled during the peak of summer and is usually well-populated with bathers, sun-bathers and people-watchers. There is (water) safety in numbers.
Meanwhile, another summer water warning has also been issued. Cawthron Institute research scientist Susie Wood says a toxic algae in the Waimea River near Appleby Bridge is the worst outbreak she has seen, and it poses a high risk to health. At least one dog is believed to have died, others made ill, and Dr Wood says the algae could be just as dangerous to people.
High, stable temperatures, low river flows and high nitrogen levels are contributing to the algal outbreak which is likely to be present in other rivers in the region too. The good news is that rain heavy enough to flush the rivers will break down the algae - though it remains to be seen whether today's rain will do the trick.