The diagonal line leading up to the bird is good. The picture is a little out of balance, nearly empty space on the left and the tanks and cart on the right. Additionally, the bird is looking to the right drawing attention to that side. I think if you had the opportunity to remove some of the empty space by stepping to the right you may have been able to improve the composition. I always been fascinated by large birds - good subject.
I agree with the comments above...and wonder if the bird would have been nervous enough to fly off if you had moved. Also, moving would have altered that diagonal line somewhat. How about the idea of getting more telephoto out of the camera (unless you were already extended), which eliminates the gas cannisters...not that they were doing much anyway)...and then waiting for the boat in the background to go more to the left---or, if it is going in the wrong direction, to get out from behind the pole? Tough subject...for me what I think I see in the lens isn't always what is produced by the camera!
well, it's a bit not sharp (also I agree with above comments... or mirroring the bird to look left. But I really like the contrast between the darkening sky and the sunlit mountains at the horizon. very nice.
To me, this picture tells a story of people on holiday at a beautifull spot, doing exciting things like diving and cruising around on a ship.. Yes, the composition could be a bit drifferent as well as the sharpness, but keep on experimenting with the settings, you'll soon be an expert. And keep on posting!