Translation:The man is swimming back and forth in the pool.
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Well, since this course also tries to improve one's English, I'd say it's because no one I know who speaks English, and I am a native speaker, says "swimming baths." Bathing pools, Swimming pools, yes. Hot springs are often designed for public use to look like pools, and are still called "baths," but no one calls them baths for swimming in. Besides, those are rarely made deep enough for such.
Sorry FredCapp but you are totally wrong. Everyone in South Yorkshire (and I'm pretty sure further afield) says 'I am going to the baths,' meaning the swimming baths, meaning swimming pool. I think it would be good to add 'swimming baths' or even just 'baths' to correct answers.
Ah, thank you. I did not know that.
That is not an American phrasing, and I never heard it when I was traveling through England (though I never did quite make it to South Yorkshire, and my time in York, itself, was very limited with no chance to discuss swimming with the locals) The way that the English and the Americans can both take the same word and make it into something completely different (napkin v towelette, and hood v bonnet come to mind) I should not have been as surprised as I was that someone might say bath and mean another sort of dipping one's self into water.
I do apologize, I did not realize that you were referencing a legitimate regionalism.
I think it comes from the time when many houses did not have bathrooms. Bathing facilities for cleaning yourself were often in the same building as swimming pools. It may be more complicated than that but I think that's the general belief. I hope you enjoyed York BTW, lovely place; pop up to Whitby next time you are there - best place on Earth.