I believe it was a large missile of some sort, earlier on was very distant smoke trail down low and vapour higher, seemed so close I was looking for a warship off the coast. Was a while before I thought to take image and it was dissipating a lot. I even turned to port to put the smoke trail viewing through my side window. I have tried to edit the image for better contrast. Can see it was much closer than the horizon, There is a full military aviation base at Bowen Airport and a notice was out that effect. Very interesting.