...apparently giant flying deformed upside down albino greyhounds are something of an achilles' heel for me.
I'm hitting the nightshift wall pretty hard, as is indicated by the fact that the sky is overcast just so I wouldn't have to futz about with a shadow, and that the location is over the open sea.
For the record, they are not floating dog turds. The sea in question is the Sargasso Sea and those are clumps of sargassum, a seaweed that grows in great clumps. See Hodgson's stories for further information (it's far more terrifying and wonderful a concept in fiction).