Translation:It is said that the watermelon is delicious.
I would like some clarification on this myself. Above if you hover over Λέγεται it gives "they say" as an alternative, but that doesn't sound passive at all. The wiktionary article on λέγομαι (and it's conjugated forms) translates it as "i am called" which fits more with the passive voice.
"they say" is not a literal translation -- literally, it is "it is said".
But another, less literal but idiomatic translation into English would be "they say".
Oh right, lol. I was definitely thinking too literally there. Thanks for the helpful perspective :D