The HMAS Canberra is a frigate that was sunk off the coast of Victoria as a artificial marine reef. It sits in less than 29m of water. Google "HMAS Canberra dive wreck" for more information.
There are about two buoys tied to the wreck. You can use them to swim downwards - but due to the wave swells - they move.
Visibility was about 5 - 8m. You can swim inside the ship and I think a swim through is possible. One of my dive team went through the ship, disappeared for 10 minutes, and came out the other side, much to my relief. The ship's bridge is easily accessible as well as the forbidding helicopter hanger. I had no desire to go into the ship's interior.
It was a very cold dive. We did it in the afternoon in late March 2010. Its the start of Autumn and the waters were very cold - compared to the tropics. 17 - 18C. Actually the 1st dive of the day at 3pm was ok. But afterwards, the sea got rougher and colder.
I was positively freezing when I descended on the 2nd dive. The only thing on my mind was "@#$% I want this dive to be over NOW."
But afterawhile I acclimatized and it was ok. I ended up being the last person on the boat.
My air consumption was pretty good considering the coldness of the water. I relaxed, I think the coldness even slowed my heart rate and breathing down. haha.
We didn't experience any sea swells that can suck you into the bowels of the ship. And looking inside - I didn't feel any desire to explore.
Fish life was minimal. There were more divers than fish. Coral life is starting to take hold - but its too early as the ship was sunk here only last year. But there were hundreds of small purple "condom size" jelly fish. I managed to get one clear shot of the things.
I'd go again in three years time from now. But right now, its not worth the bother of long distance travel unless you're in the vicinity.