A refreshing dip became rather hazardous for swimmers today when a large bloom of lion's mane jellyfish washed into Port Phillip Bay in Victoria.
Sandringham Beach in Melbourne was quickly closed when the swarm of creatures appeared.
Sandringham Life Saving Club shared the footage.
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"Please avoid the water. Out patrollers will be on hand but the beach will be closed," it said.
Stings from their large tentacles are known to cause intense pain, redness and itching.