Is there public transport in and around Cairns, Australia out of regular hours?

According to the WikiTravel article on Port Douglas there are at least two companies offering shared and group transport between Cairns and Port Douglas:

• Exemplar Coaches and Limousines

• Sun Palm Transport

Niether specifically mentions Oak Beach, but this is a tourism-driven part of the country and airport shuttles are generally extremely flexible with where they will pick up and drop off. But since you are a group it might work out cheaper than renting a car to use one of the group services these companies also offer.

You might even find they have planned especially for the eclipse. I highly recommend contacting both companies. See if there are special eclipse even services, find out if the size of your group is a good fit for a private group transfer, and compare the prices to car rental.

• Exemplar meets every flight and offers seats in a coach for $34 per person and charter vehicles for 7 people for $210.

• Sun Palm has a regular schedule beginning at 3 a.m. and offers seats in a coach for $35 per person. They require you to contact them about event and group transport so I can't include a price here for you.

If you go for a group charter you might even find the price slightly lower for the shorter distance to Oak Beach. Haggle!