Happy Feet was successfully released at 10:28 NZST on Sunday 4 September from Niwa's research vessel Tangaroa.
Weather conditions at the time were "the best that could be expected in the Southern Ocean at this time of year" according to the vessel captain Roger Goodison. The wind was 20 knots from the northwest with a 3-4 metre swell. Happy Feet was released using the specially constructed 'hydroslide' built by the Tangaroa crew.