[TOMT] Recent [movie] about a bunch of friends on a boat. Suspense/thriller from a few years ago. It's not "Triangle"

I recall seeing the trailer and wanting to see the movie, but never got around to it. It went something like: a bunch of friends are in an enclosed space. I'm 99% sure it was a boat. One of them dies mysteriously or they collectively decide to kill someone, and everyone is suspicious of each other and there is a lot of yelling and sweating and walking slowly, holding a weapon of some sort.

I remember an axe, some foxy ladies, flashlights. Most of the shots were brown-toned and heavily shadowed.

For some reason, I remember it being Australian.