Locating humpback whale singers underwater is a challenge, but it's fun. There's nothing quite like tracking down a singer bit-by-bit, swimming along, scanning the water until the vague outline of a cetacean emerges from the misty blue haze.
Sound travels so well underwater that it's extremely difficult to gauge direction and distance. Also, singers can stay down for extended periods of time, often diving too deep to see, sometimes swimming as they sing, sometimes sitting in plain sight but countershaded so well that you cruise right past them.
We found 14 singers this season, which is pretty high. Single-digit tallies are more common, not necessarily because there aren't more singers around, but due in large part to the amount of time and effort it takes to track a singing whale down.
We came across the first singer of the season on 13 August, pictured below:
First humpback whale singer I came across in the 2011 season.
Note the lopsided fluke.
The water wasn't clear (bad viz. characterised the season), but the whale wasn't too deep, about 15m (around 50ft) or less at the fluke from what I remember. It stuck around long enough for everyone to get a good look, and for my friends Debbie and George to record some video. (Debbie actually recorded the video. It was enough for George just to stay out of the way.)
They just forwarded me the following audio tracks of the singer, which they extracted from the video footage (Thanks Debbie, George!).
It may not come across in these recordings, but it seemed like the bass this year wasn't as deep and booming as normal. I hung directly overhead this one and several others this season, and I didn't get the same intense reverberation in my body as I have in the past.
Here's a video from the 2010 season showing what it's like to make a short courtesy call to a singing humpback whale. This one was considerably deeper, 20-25m at the fluke.