I have felt the sting of the box jellyfish whilst spear fishing, it was only a minor sting that ran up my right side. The stinging cells are within the tentacles and are called Nematocysts, vinegar deactivates these Nematocysts and prevents most of them from further firing off, lessening the degree of envenomation. Methylated spirits should never be used as this triggers off more stinging cells upon contact, the stinger season is either side of October to may. I was quite surprised at the amount they were pulling in. The box jelly can grow up to 20cm across the bell.
Sea snakes are fairly common in tropical waters and are encountered by many divers.
They are usually quite shy and retiring like their terrestrial relatives, and like their land based relatives they have developed some very unusual characteristics to suit their marine habitat. They are air breathers just like land snakes. The interesting adaptations are, valvular nostrils to prevent water from entering their respiratory system, a paddle shaped tail for better propulsion within a marine environment, also their right lung extends all the way down to the tail region, thus increasing their oxygen capacity, they can also absorb oxygen through their skin. There have been no recorded deaths from sea snake bites here in Australia, but there is no doubt they do have the potential to kill. The cone shellfish can be found right around the northern coastline of Australia stretching into the more southerly regions.