"As the FNG you will always get the least desirable jobs. This normally incorporates being a guide for snorkelers who aren't even going diving"
Oh man, the FNG is the Dirty Harry of diving, always getting the dirtiest jobs! :-0
Or maybe the Forrest (N) Gump of diving, since I'm pretty sure Gary Sinise called Tom Hanks an "FNG" in that movie: "life's like a box of snorkelers, you never know which one you're gonna get!"
In fact, "DiveMaster" could easily be a movie, starring Will Ferrell as the FNG Divemaster who has to take Michael Moore and Melissa McCarthy on a snorkeling trip: He knows he's gonna get a big tip, but she wants a selfie with a dolphin, and he wants to talk politics, and unbeknownst to Ferrell, a great white shark has been spotted in the local waters. Can he teach McCarthy how to put on a snorkeling mask, when she keeps hyperventilating, can he save Moore after he steps on a sea urchin and the shark can smell his blood? Does Ferrell even want to save these people? Coming soon to a movie theater near you!
I love that you told us about the underwater navigation snafu. It's the details that make a story! :)