I'm editing away here, and have a mental block with this! Is it - the boats got more and more scruffy the further they walked from the gateway or farther? I should know...but I don't.
It doesn't matter too much but 'farther' tends to be used for actual distance, whereas 'further' tends to be more for emotional/mental etc distance - 'He felt she was moving further away from him with every fart he let rip'. Well, actually that's more likely to be 'farther', but you get the point.
I'm more concerned with you saying the boats got more scruffy the fu/arther away walked from the gateway. Maybe it's because I have a very visual mind, but I take that comment at face value and so picture boats getting scruffier, etc. But then I think, how can that be? Is there something about being nearer the gateway that makes them tidy up a bit? If they don't actually get scruffier, I'd recommend not saying this kind of thing. It's okay when you're talking to friends, who realise you're exaggerating, but not in a written story.
And as for 'got' - I know it's old-fashioned, but I think it's best to avoid filler words like that, and instead find a more specific one.
Or you could say the boats 'seemed' to get scruffier etc - that tells us that we're in your characters' POV where it's okay to make personalised observations.
I like the idea of boats walking. Especially since, in Russian, they "swim" rather than "sail". Maybe they got cold and decided to sunbathe for a while.