请问去大堡礁是不是都是由cairns出发的？

I don't think Cairns is the only choice. The Great Barrier Reef is all along the east coast of Queensland. You may consider a start from its north or south end. I did from Cairns only because it is well connected by air. It's a small town, even no beaches seems. I saw very nice photos of Whitsunday Island, which is also connected by air from major cities.

About diving, there're some info here:

http://www.queenslandholidays.com.au/things-to-see-and-do/nature-and-wildlife/great-barrier-reef-and-islands.cfm

I would recommend smaller groups.

Cairns其实并不是好的选择，因为真正好玩的地方离那里都有一段距离，可以去palm cove/port douglas/whitsunday（local同事强烈推荐）／townsville

有其他地方出发，不过Cairns最方便，选择多，如果初次去，这里出发最好。

船宿潜水一般都Cairns出发,浮潜和体验潜去道格拉斯港比较好.

我在游四海旅游商城买的这一款哦~

【费用包含】
交通
*往返大堡礁的游轮/直升机*免费饭店接送（船去船回行程皆不提供）
行程体验*免费使用全套浮潜用具（含水母衣）*浮潜技巧教学*大堡礁生态珊瑚礁生态讲解*半潜艇探索海底*海底观察站*绿岛全岛导览（参加双礁行程者）
餐食
*丰盛海鲜自助餐
*开船前提供热茶冷饮

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