Seeking help with 5 days plan for Port Douglas (Cairns) Aulstralia

What an amazing trip! I can offer a couple small bits of personal experience. I was in Australia 8 years ago- caveat, it was July so that's a factor for weather
I based in Cairns. Your walk along the harbor area sounds just the right amount of time, plus to see the shops in between all the tour operator offices. I also remember trees filled with bats?!
I can't help you for Port Douglas but I did a night tour of the Daintree that was fantastic (started mid- afternoon) and was also unexpectedly impressed with Hartley's:
https://www.crocodileadventures.com/
I thought it would be kitschy which admittedly a bit was, but the boat tour and exhibition was really educational. Incredible photos. And I am not a zoo person at all!
I hope this is helpful!

There is a lot to do if you have 5 days that your non-swimming wife may enjoy whilst in FNQ.

The Atherton Tablelands deserve at least a day of your time. Wildlife, waterfalls, rainforest walks, cute towns, mango winery gorgeous landscapes, etc.

In Cairns, I always visit the Tanks, if you like art, and the Botanical gardens which feature many tropical fruit trees and if there at the right time, can be sampled. The northern beaches are also worth a visit. Palm Cove, Clifton & Trinity are all beautiful. There is a great walk from Clifton to Palm Cove which also has a market which is more intimate than Port Douglas

Hi Brad, your trip plan looks good, Port Douglas is a favourite holiday spot for us, we have been going there every year for the past 19 years! Your accomodation is in a great location, easy walk to supermarket, cafes and restaurants. In terms of restaurants, our favourites are the Tin Shed (upstairs bar is a good spot to watch the tour boats returning late afternoon), Salsa for a slightly more up market experience and if you really want to push the boat out or celebrate a special event Nautilus (we have only been once but enjoyed it immensely). In terms of cafes Cafe Fresq, another favourite of ours is great for brunch or lunch. There is also 3 pubs and several other restaurants and cafes, spoilt for choice really.
You can book reef trips the day before to take advantage of the weather conditions but if you have a booking and the weather on the day is not so good the tour companies are usually very good in accomodating changes.
The Low Isles trip is lovely, there are lots of green turtles and plenty of coral and fish to see although the water is much more shallow there than at other areas of the reef. You can also walk around the main island, not a long walk but very interesting.
For the other reef trip, I would avoid the bigger groups such as Quicksilver, nothing wrong with them but they tend to cruise out to a pontoon and stay there and the reef around the area is not as spectacular as elsewhere. We have been on Wavelength and Sailaway and enjoyed both.
Cape tribulation is a great day out, look out for the ice cream farms for a tropical treat, our favourite is the Daintree Ice Cream Company, on the left side as you travel north. Daintree Village is an interesting short detour either going to or coming back from Cape Trib and if you are interested in crocodile spotting there are short boat trips from there. We have also enjoyed or visits to the Daintree Discovery Centre.
Mossman Gorge is well worth a visit, the rainforest walks are lovely and the visitors centre has a nice shop and gallery showcasing Indigenous art. We usually spend a couple of hours there and a whole day on the Cape Trib trip even after many trips but then it is very different from our part of Australia.
Hope that you enjoy your trip to the antipodes but especially to Port Douglas.

Thank you so much for the advice… and restaurant tips.
(I like having tentative plans and then will be able to work with what the weather brings.)
As I noted before, my wife is not so big on snorkeling.
There are so many potential ventures and I want to leave some time to enjoy the local beach / town. With that in mind, my updated plan is to create one full day road trip. (We have rental car.) I mapped the potential to do Mossman Gorge, Daintree Cruise, and on toward Cape Tribulation…but only go to Thorton Beach. It would appear doable, but there are no early Dreamtime Walk Tours at Mossman that early…so we would miss that and still have long day. My hope is that we might be able to do Mossman on another afternoon.

For the Low Isles trip that my wife could enjoy doing as well…I am leaning towards the later start but longer 10am to 4:30pm trip (Wavedancer https://wavedancerlowisles.com/) rather than the early half day or afternoon (Calypso).

May 15: Arrive noon; Rent car, visit Cairns waterfront; drive to Port Douglass (1.5hr) Stay: Port Douglass (5 nights)
May 16: Half Day Snorkeling trip / Beach (Possible Sat. 5:30 worship service)
May 17: Visit Sunday Market (open 8:00 am to 1:30) / Half Day outing (Mossman Gorge) or beach
May 18: Full day trip to Mossman Gorge, Daintree Rainforest Cruise and start of Cape
May 19: Half Day GBR (Brad) / Beach
May 20: Return drive up to Cairns for an 11:40am flight to Brisbane

Any added thoughts would be welcome..
Thanks.
Brad

Hi Brad, thinking about your trip is reminding me of all of the great times we have had in Port Douglas, our next visit is going to be a busy one! When we went out the Low Isles we took the same or a similar trip as the Wave Dancer tour, we really enjoyed it, lunch moored off the Low Isles was lovely as was the trip out and back to Port. For your other snorkelling outings, have you considered a day long trip that goes to a few different dive sites rather than 2 half days? All of our reef trips have been full days and we have enjoyed all. The trips are well catered for with morning and afternoon tea plus lunch and all equipment, snorkels, fins etc provided. I would also give serious thought to taking a stand alone Mossman Gorge trip so that you could include a Dreamtime Walk Tour, it will really add to your experience of the place. I can't comment much on beach days, I burn very easily so we tend to go to the beach later in the day and only to walk. You will be there at the end of the stinger season but the stinger nets should still be up and the beach is patrolled every day I believe. Always swim "between the flags" for your own safety, it is not a surf beach but it is monitored for crocodiles who will occasionally cruise by. On the subject of which, the Surf Life Saving Club restaurant "The Surfy" has great food and is close to the beach and your accomodation. I am not sure if it has reopened again yet after storm damage earlier this year, but the Flagstaff Hill walking trail that goes from the beach near your accomodation round to the Rex Smeal Park on the other side of the little peninsula and has beautiful views.