My wife and I are planning to buy a sailboat (30-34 footer) and are planning to sail around the great barrier reef in winter. Is the winter weather on the great barrier reef in winter likely to make this a rough trip? Are there many accessible lagoons on the outer reef where it is safe to enter/exit and anchor to avoid any rough weather with a boat draft of 1.58 metres? Any advice or recommendations is appreciated.

Suggest you purchase Alan Lucas's Cruising the Coral Coast. Basically the bible for cruising Qld, including the Great Barrier Reef.

www.alanlucascruisingguides.com/shop/p/product-name-5-4nyha

Sailing the Reef is not limited to winter only, but sailing window.
Also there is more than hand full of lagoons, North West Isl., Percy, East Hope, Lizard etc.