There are lots of little things in this section that make translating fun. If you are in class, make an experiment. Have everyone do their own translation on this section and compare notes.
21:5. Jesus calls out to them, παιδία, a word describing "a child, normally below the age of puberty." It can also be used to describe someone “who is treasured in the way a parent treasures a child” (BDAG). Translations try words like “friends,” “children,” and “fellows,” none of which work in this historical situation. I wonder how a bunch of grown fishermen first responded when a stranger yelled out over the water, “Hey you prepubescent kids.” Sounds almost like the Goonies.
21:6. Jesus then tells them to throw their nets on the right side of the boat. I would not appreciate it if you threw something on the side of my boat; however, I wouldn't mind if you threw something over the right side of the boat. I know both “on” and “over” are possible, but what would you choose? If you chose the first, I wouldn't take you wake boarding.
21:7. Was Peter naked? γυμνός can mean “naked,” or it can mean poorly dressed. BDAG sites this verse, saying it could mean he did not have on is outer garment, and also cites Isaiah's "nakedness" in Is 20:2. Either way, what would you choose?
21:12. The disciples hauled in the 153 fish, and John writes that “none of the disciples dared (ἐτόλμα) to ask him, ‘Who are you?’ They knew it was the Lord” (NIV). τολμάω is an interesting word. BDAG’s entry says, “to show boldness or resolution in the face of danger, opposition, or a problem, dare, bring oneself to (do someth[ing]).” Almost all translations say “dared” except the NASB, which has “ventured.”
But think about. Why would a lack of boldness cause them to not ask an obvious, rather stupid question. I have a hard time thinking that boldness led them to silence. It seems much more likely that none of them were rash enough to ask a dumb question; they knew who he was. But bold? Can you imagine one of the disciples thinking, “I’m so bold that I’m not going to ask a silly, obvious question”?
Nothing earthshaking here, but it is a fun exercise to translate this passage not for a first year Greek class but for reading in church. Give it a shot.