From video doorbells to robot vacuum cleaners, modern technologies are infiltrating our homes. But not all new gadgets are necessarily good or bad. Some can even be lifesaving.

Every day before dawn, pilgrims clutching towels cut through the spray of crashing waves to swim in patches of tamed ocean that rise like eerily beautiful oases between the sea and the cliffs. These sdy pools, scattered along the rugged Sydney coastline, are the site of Australia’s love affair with the ocean that stretches back more than 200 years.

Carved from rock clusters, flooded at high tide and surrounded by seawater and rocks, these oversize, man-made tide pools offer refuge from the rough surf of the wild Australian coast and a distinctive brand of offbeat culture that has made the place famous. Some have Victorian changing pavilions, others are run by swimming clubs with quaint names, and many date from the early 20th century, when they were built as protection from the powerful surf.

But despite their pristine reputation, the pools remain vulnerable to ecological change. Jellyfish wash in with the tide and one local reports a 2.4-metre shark lurking around their pool, while scientists at Bilgola, on Sydney’s Northern Beaches, are trying to recreate sea pools for the tiny creatures that were displaced by the pools’ concrete walls.

The film’s most intriguing angles get short shrift, though. The fact that swimmers are not only millionaires and paupers but also young and old is not explored, nor the ways class plays out in their shared experience of these salty, beautiful, and teeming waters. The euphoria that comes with this communal swimming experience isn’t fully examined either.

There are nearly 100 ocean pools in NSW alone, all of which were carved or dynamited from the headlands along Sydney’s rough coastline in response to the power and beauty of the raw coastline. The salty, cold waters are a magnet for photographers and attract swimmers of all ages. Some are in their 90s and find the salt water an elixir of youth.

While the film is about these pools and our love of them, it is also about the broader issue of how our oceans are being compromised by climate change. With the NSW government and local councils failing to protect our coastline, it is up to community groups to save and restore some of its most spectacular gems, and to ensure that we preserve for future generations the natural and cultural wonders of Australia’s coastal jewels.