"(Someone) swims" ex. The prince swims. 王子様は泳がれる。

I think 泳がれる is the Keigo version of 泳ぐ.

「泳がれる」is whats called the "passive form" of the verb「泳ぐ」which means "to swim." English has passive form verbs too just like Japanese but its hard to directly translate the word by itself without knowing the context around it. This is a good article explaining passive form -> http://www.guidetojapanese.org/learn/grammar/causepass The difference between the two is that if you use 「泳ぐ」 you are saying - someone - "is swimming", whereas 「泳がれる」is more like something is "being swum" . I'm trying to think of an example sentence using it, however I think it's uncommon to refer to swimming in the passive tense. Some people may use「泳がれる」to mean 「泳げる」which is potential form ("someone can swim") for example in dialect, however thats considered grammatically incorrect. But yeah, translating the word by itself is hard but it is roughly - something is - "being swum" (- by someone -). The bit about "someone" may be implied by the sentence but its not actually within the verb form. Hopefully this helps.