In a previous life I worked as a pearl diver and for a while we were based out of Cooktown FNQ (Far North Queensland). There was a legendary croc in the Endeavour River which IIRC was 20ft. long. This croc had a hatred of outboard engines, apparently it would leap out of the water and sink it's teeth into the head of your engine. As most folk had "tin tubs" which were probably about 20 ft. long I would imagine that this would have been a brown trouser moment. I'm not sure but but I think someone eventually shot it.
Why did I dive in shark and crocodile infested waters? I was young and I wanted (needed) the money.
P.S. Back in the safety of Cairns I met all sorts of people. For your amusement here are two of them.
1) An American who had a tiger proof tent and Kevlar anti-snake leggings.
2) An Aussie who relocated crocs from Aboriginal encampments. He wore shorts and had no armour at all. However he did give me this advice.
A croc can outrun you, it can possibly go at 30mph for 50 yds, somewhere around there. He told me that if you are walking along a river bank and see the crocs slide into the water they are not hiding, they are hunting you.
And the last piece of advice was this, if you don't have a gun climb a tree.