You have to leave Loch Ness with the "loops" photo and come back.
There are two players you have to beat. The first one, with the mustache, has the rowboat ticket. Once you get the photo on the rowboat, you return to Mews.
When you go back to Loch Ness, you play the man who has the submarine ticket. Get the photo and bring it back to the pub. You will now play the first player again.
Nothing, apparently. However, he gives you the pennywhistle when the darts player is a sore loser.
It is at Loch Ness.
There does not seem to be a horn on Cryptids Island. There is a flute (a pennywhistle) which you receive after the submarine ride, after you defeat the sore loser at darts again.
They aren't arrows, they are darts (see the related question).
The pipe is a "pennywhistle." You get it when you beat the first darts player the second time, after you have taken the submarine ride and brought your photo back to the pub.
Beat the first player (wearing glasses) and take the rowboat ride, and bring the photo back to Mews. Return to play the other two players to win a submarine ticket (with better darts).
You only play darts at the Pub to win tickets to the rowboat and submarine rides. The third time you play is against the first player you played. On your first trip to Loch Ness, you get the digital camera and play darts to get a rowboat ticket. You get a photo and take it back to the Mews lab. On your return to Loch Ness, you play darts against a second player to earn a Submarine ride, and photograph the "Nessie" at the bottom of the Loch. Return to the Pub to find it is a movie prop, but beat the first player again and you get a Pennywhistle from the bartender.
yes there is
You win at darts a second time and get a submarine ticket.
The Pub is to the right of the loch at Loch Ness. You will play darts there to win the tickets to the rowboat and submarine.
The first player (mustache and glasses) has the Rowboat Ticket. You have to get a photo from the boat and return it to Mews. When you come back to Loch Ness, you play against one of the other two for a Submarine ticket. You bring that photo back to the Pub, where you find it isn't real, but get to play the first player again.
On your first visit to Loch Ness, you can win a rowboat ticket by playing darts at the Pub (to the right of the Loch).