I had a Bluw Swedish drake with a crest just like this. He lived with my other ducks in the coop and went around the yard and to the creek with them all. I did notice that when the grass was wet or when it rained, his crest would get very damp at the 'bottom' and he walked with butt higher, like it was really heavy.
I considered having my vet remove some of the extra skin to reduce the size of the crest, for his sake and spine/neck health. but i finally decided to just find him a good dry pet home where he'd get lots of special attention. I was just too worried about putting a duck under for surgery & he was usually fine if he was dry.