Nice.

I was on a small 4-5m boat up at Ningaloo when a whale popped up about 15m in front - surfaced, cruised, and then went straight under 5-10m before us. I swear i was waiting for bump and a big tip out into the blue. Freaky at 1st but amazing. You just don't realise what they are like till you get within earshot in their environment...
As for your experience - what a ripper! My french mate would put it this way "Farque le duck!" Did the big guy give you a wink and ask what size kite you were on?