Towing the boat to Cairns is no big deal if you are set up for the tow. Lived there most of my life and if you want to go out to the reef forget the charter boats. Towed 19 ft boats to the cape with no problems. Can give you some marks if you want for the Cairns area. Have boat will travel is the approach to take and don't understand what the issue is. Yep you may get there and the conditions may not be perfect but that's life.