Beautifully sharp and nice low angle view of the bird, Thijs. BG works well. Looks to have been a successful fishing trip with the bird having a bulging crop.
Nice to see a juvi, the adults get all the attention.
Sharp, well exposed. I like the comp, sense of gliding over the ocean. Might prefer a slight bit more room behind, and a bit more to the right.
You could consider running a linear burn or multiply selection on the whites on the tail where the exposure looks just a bit hot. (The overall exposure balance looks good)
I agree with Randy that it is nice to see a juvenile gannet! Good exposure overall with just a bit of hot whites on the rump. I like the water texture too. Comp-wise I find the subject too high in the frame, and I too wish for a bit more room behind it.
I've never seen a juvenile Gannet before. You did well to capture it with such nice sharpness on a pelagic trip. Whites have been addressed (I might have gone with neutral exposure here). I do wish the bird was flying towards us.