Every November or so, Cairns and the tropical North of Australia is visited by what we call Marine Stingers. This refers to the Box Jellyfish and the six or so species that are commonly called Irukandji.

These are 2 very different jellyfish behaving in 2 very different ways. i won't get too much into the scientific side of things but you can read that here if you want to, www.visitcairns.com.au/stingerseasoncairns.htm . What this article is about is how we deal with them.

The Box Jellyfish generally isn't too much of a worry until we have had our first big dump of rain for the wet season. There can be a few around before that but the first big dump brings them all out from the creeks and rivers to the inshore waters. These jellyfish do not inhabit the Great Barrier Reef, so you are safe while snorkelling/diving etc. They are more prevalent around creek and rivermouths and beaches close to such. Most beaches in cairns have stinger nets and these are perfectly safe from Box Jellyfish.
If you do need to go in the water, avoid stirred up cloudy water. A box Jelly is quite large and can be seen if being observant in clear water. When fishing/launching boast etc the local wear lycra stinger suits. A cheap alternative is to wear nylon stockings.

The Irukandji Jellyfish is an oceanic Jelly which can be found on the Reef also. It is more prevalent in Summer and also when the winds are northerly. These guys can be as small as your thumbnail so are impossible to spot in the water. The only prevention from these guys is to wear a full body lycra suit. They can penetrate the stinger nets (thats why my daughter always wears a stinger suit, even while in the nets).

We tend to avoid the beaches in the wet season, instead concentrating on some of the rainforest creeks with their shaded refreshing waters. These can be too cold in winter, so it makes a nice change.

You'll have to meet a local to find the best ones though................