Thanks tropo. Robinson Cruscoe feeling indeed! A few years ago our neighbors here in CT joined us on one of our regular trips to a trip to Australia, including a few days on Heron Island. They had booked only 3 nights on the island to make time for a trip north to PD. We stayed 5 nights. They liked the island so much they tried to extend their stay but couldn't change their other travel arrangements, unfortunately. Heron Island was undoubtedly the highlight of their Australia trip, as it has been for us on 5 occasions now.

RalphR - apart from Heron Island, many years ago at various times, I camped with fishing mates on the following islands - Fairfax Island, Lady Musgrave Island, North West Island. It was a wonderful experience living on a coral cay island, with no other visitors, so close to nature. These days, they have banned camping on some islands now, however, camping is still allowed to Lady Musgrave Island, after getting a camping permit (something we didn't have to do in the past), and the proviso, that you take all your drinking water, which we had to do also.

i vote port douglas
id rather spend four days on mainland than an island unless youre honeymooning
mainland gives you more choice
esp if the weather is unpredictable
or if youre not up for another beach day
from port douglas you have more choices...not just the reef but the cape tribulation area..mossman gorge and cairns and its hinterland..you can get the skyrail to kuranda and spend a day at the markets and bird sanctuary..lots to see..go hot air ballooning..all tours you can book from your hotel desk
palm cove is another nice spot you can visit south of port douglas
and maybe even go so far as dunk island if you get a car...we did that when we stayed in cairns one year..spent the day on dunk island as a bit of a contrast...its more a family island tho