One South Coast man got a stinging surprise when he visited Barlings Beach on Friday.
Brett Wallensky discovered a dense mat of bluebottles washed up on the rocks, south of Batemans Bay.
While the beachcomber said he had "never seen thousands of bluebottles in one spot before", those heading to the coast this summer are likely to see a whole lot of them.
Their blue, baloon-like sails are a common sight in Australian waters during the warmer months. Dragging long tentacles beneath the surface, the pretty but mysterious sea dweller is known to deliver a sharp sting.
Blue bottles are siphonphores, a strange kind of colonial jellyfish. Rather than being a single organism, individuals (or "zooids") each make up parts of the colony's tentacles, digestive system and more.
Fortunately, Australian blue bottles are less venomous than their northern cousin, the Atlantic Portuguese Man-o'-War or "floating terror".
But beachgoers are advised to stay well clear, as even dead blue bottles can deliver a painful sting lasting up to a few minutes or several hours.
While past remedies have included everything from vinegar to urine to warm beer, removing the stinger and running the affected area in hot water is now considered the best treatment.
More than 10,000 people report being stung by bluebottles in Australia every year, and that number can climb to 30,000 in peak years.
Last summer, blue bottle stings were reported to rise around the country, with beaches in NSW, WA and Queensland "overrun".