I recognise that photograph. It was taken at Dunedin, New Zealand in January 1938.
G-ADUT “
Centaurus” arrived at Auckland from Sydney on 27th December 1937 at the end of the long survey flight from Southampton. Already moored at Mechanics Bay, Auckland was Pan American's Sikorsky S-42B NC-16734 “
Samoan Clipper” which had arrived the day before.
On 31st December, “
Centaurus” flew from Auckland to Wellington, alighting on Evans Bay.
On 3rd January 1938, the flying-boat flew from Wellington to Lyttleton (Christchurch's port).
On 4th January, “
Centaurus” flew from Lyttleton to Dunedin, alighting on Otago Harbour.
On 5th January, “
Centaurus” flew from Dunedin to Wellington, where it was refuelled at Evans Bay, then took-off again and flew to Mechanics Bay, Auckland.
On 6th January, the flying-boat took invited dignitaries on a joyride flight from Auckland north to Parengarenga harbour (an overflight only with no alighting), then returned to Auckland.
On 10th January 1938, “
Centaurus” departed Auckland for Sydney at the start of the long flight back to Southampton.
The photograph is one of a large number available online from the National Library of New Zealand's website.
http://natlib.govt.nzJust search for Centaurus and you will discover 153 photographs of “
Centaurus” in New Zealand between 27th December 1937 and 10th January 1938, with most of those images from Whites Aviation.
If you refine your search, you can even locate some photographs of “
Centaurus” and “
Samoan Clipper” moored together on the Waitemata Harbour at Mechanics Bay, Auckland.