Torpedos on the J4 submarine

About the wreck

The J class submarines were built by the British in a hurry during WWI in response to a rumour that the Germans had invented a faster submarine. After the war, the remaining 6 of the original fleet of 7 was gifted to the Royal Australian Navy, and travelled across the world to eventually be based out of Geelong. After a very expensive refit on arrival, the running costs for the J class subs was found to be a fair bit higher than estimated. Built using old technology, they also became obsolete in fairly short order. With budget cuts for the Navy, the subs were handed over for salvage and scuttling.

Two of the six subs ended up inside the Bay, one as part of the Sandringham breakwater, and one sunk inside the military zone associated with Swan Island. The other four are outside the 3 mile limit outside the Heads in varying depths, and make for popular dive sites. The J4 is also known as the Shallow Sub or the 26m Sub, and sits upright on the sand in 26m. She was rediscovered by divers in 1984, with a plaque in front of the conning tower commemorating the occasion. The J4 is about 90m long, and unless conditions are particularly bad it’s quite easy to swim a relaxed lap of the wreck on the average dive.

About the dive

This particular dive took place in the middle of winter, with water temperatures of about 13 degrees. After a week of light northerly winds, the ocean through the Heads was completely flat. The vis was correspondingly good as we descended and despite it being a bit cloudy up top there was lots of sunlight coming through. The shot landed in approximately the middle of the wreck, and KA and I headed past the conning tower on the way to the bow. A large school of little hula fish hanging around the conning tower provided a momentary distraction, as you can see in the second picture.

The end of the bow has broken off, and a section about five metres long sits separately about a metre back and slightly offset to the main body of the submarine. This large opening into the main body of the sub can result in surge being funnelled into the wreck and water emerging from the hatches further aft at high speed. There are some days when getting close to any of the openings to this sub is a bad idea – luckily this wasn’t one of them.

About the shot

After being the first buddy pair off the boat and into the water, we were also the first to arrive at the bow of the wreck. The inhabitant bullseyes, who must be used to regular invasions of noisy divers, were still hanging around, and I took advantage of the moment. After a little bit of strobe rearranging to get the light in the right places, this shot was fairly easy.

I also got lucky with the perch in the top right corner choosing to swim over my shoulder just as I clicked the shutter. If this little guy had chosen to be in front of the strobe he would have given himself sunburn and created a fabulous hotspot. Instead he’s just caught just enough of the reflected light from the left hand strobe to be a feature.

I like the depth that the shadows add to this picture. One of the challenges of wide angle photography for me has been using two strobes to get good light coverage across the whole frame. For a lot of my ocean dives, this has resulted in flat pictures, similar to those in caves without a background light source. By angling the strobes appropriately and having them at different power settings, the shot gives good view of one of the very recognisable parts of the wreck. Add in a nice depth of field and some fish for scale and you’re set.