He said days spent there begin at the crack of dawn, when he heads to the beach to catch breakfast to share with the friends or family who have joined him on the trip. After this, the day is spent relaxing, kayaking and writing when he feels inspired.
"It always gets the old creative juices flowing."
Otherwise, he enjoys spending time in Auckland at the beginning of January when everyone has left the city.
"It's possibly the best time to spend in Auckland, because it's so depopulated; it's a joy to drive on a deserted motorway."
He said all he needed for his ideal summer was great weather, good company and a beautiful location like the Coromandel.
"Plus it never hurts to have a few fish swimming around to put on the plate."
Sinclair is known for his screenwriting partnership with Sir Peter Jackson and Frances Walsh, notably on the second Lord of The Rings film, The Two Towers.