How do you capture Nessie on cryptids island?

Answer 1

You can find her and photograph her, but capture is not something you can do.

You will have to make two trips to Loch Ness. On the first, you get the camera and play darts to get a rowboat ticket. Then you take the rowboat photo (Nessie loops) and go back to Mews. He sees they are just truck tires.

On the second trip, beat the other dart players to get the submarine ticket, and photograph an odd Nessie head on the bottom of the Loch. Take it back to the Pub, where it proves to be a hoax. When you beat the "original" dart player again, he is a poor loser. The bartender gives you the pennywhistle instead. Take the rowboat out yourself and go far left to a lagoon where the whistle will summon Nessie.