Decided to take the flight to Stewart island rather than the ferry. We booked well in advance as we needed to be on the Island at a particular time. Booked in at Invercargill Airport after leaving the hire car in the car park. Plenty of spaces. The airport is very new and pleasant with a small cafe available for drinks and snacks.
Didn't have to go through any security. Luggage weight is limited so we only took backpacks. The plane only takes 9 passengers and is very small and somewhat elderly. The pilot was a young man who definitely enjoyed flying the plane. It was a very windy and wild trip over and although only 15 minutes it was great. We had a good view of Invercargill and Stewart Island. The pilot expertly landed the plane despite the windy conditions. We landed on a tarmac strip in a field. A minibus then picks you up along with your luggage and delivers you to the centre of Oban.
On our return you book in at the Post Office to await the minibus. Going back I asked the pilot if my wife could sit next to him as she loves planes. He agreed and she had a lovely trip back. Great experience and, in my view, a better bet than the long ferry journey but not for the nervous types!