I was just browsing races in my area and came across this. It's actually a qualifier race for Aquathon World Championships in New Zealand (who knew that this even existed?). I looked at last years results and there were about 4 people in my age group. To qualify for Worlds you have to be in the top ten in your age group and then if people decline they will roll down to the top 14.
It does seem a bit different than last year so maybe there will be more people registered, who knows. The swim is 1500 meters and the run is a 10k. It should be fun.