We went on the Prima Boat Trip around the Whitsundays in December 2010.
I would strongly NOT recommend the Prima boat to anybody. The cabins are tiny, hot and uncomfortable. The boat is also quite small especially when there are over 10 people on it. The food was disgusting, frozen 'ready made' meals I wouldn't serve to a dog.
Maybe we caught Captain Steve on a bad day (2 days that is) but he was very unfriendly, he did show glimmers of passion for the area but this was largely overawed by his rudeness and grumpiness.
The whole fibe on the boat wasn't great, probably down to the Captain and the ships mate. To be honest there was a nice trainee German girl on the boat who was normal.
To top it all off every night the owner of the boat company sailed allong side our boat in his luxary boat and had his BBQ with fresh fish caught that day while we ate our defrosted 'food'.
The heat at night was unbearable and for what we paid for the trip we expected to have air con or even a fan at least.
I would recommend you try getting kidnapped by Somalian pirates rather than go on the Prima boat around the Whitsundays.
Do sail around the Whitsundays as it is amazing just be careful on what boat you pick. The travel agents down on Arile Beach will recommend the best boats, pay the few dollars extra as you want to remember the trip for, unfortunately we trusted reviews on the net and booked before we arrived to Arlie Beach.