I did a short trip 4 day trip down to Whyalla in South Australia's Spencer Gulf in May of this year, which is the start of the annual mating aggregation of the Giant Australian Cuttlefish (Sepia apama) - the world's largest cuttlefish.
I had heard and read a lot about the event and had wanted to do it for ages - glad I did as it really is quite unique.
The cuttlefish are literally everywhere in about 8-10m just off the shore and it's all about sex.... The males outnumber the females by up to 11:1 and the big alpha males dominate, so the smaller males try all sorts of tactics to get their share - including pretending to be a female so they can sneak in for a quick one!
It was all vaguely reminiscent of a bar I used to frequent in my youth, but that's another story....
The bottom line is that so intent are they on the sexual act, they ignore you and most of my images were taken with the Tokina 10-17 fish-eye zoom, mainly set at 10mm and inches away from them. Plus I was REALLY lucky on the first dive and got some "cathedral lighting".
I will write up a location report and an article when I get time, but the images from the trip can be seen on this LINK to my site www.indopacificimages.com.