You don't play the same player, and you have to leave Loch Ness and come back after showing Mews the rowboat photo. Then one of the other players who has the submarine ticket will play you.
The first player (who lost the rowboat tciket) will leave while you are showing the "humps" photo to Mews. However, once you take the submarine ride, and get another photo, you have to return to show it to the men at the pub. Once that photo is discredited, the first player shows up again to challenge you.
You win at darts a second time and get a submarine ticket.
you have to go to the pub and beat the man who doesn't belive in Nessie at darts
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.
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).
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.
You can only get the submarine ticket on your second trip to Loch Ness. On your first trip, you win a boat trip by playing darts, and get a photo to show Mews. Although it is only some tires in the water, there is something else in the photo. Go back to Loch Ness and play darts against one of the other two guys, to get a submarine ticket. You have to take a photo and go back to show it to them at the pub.
Before you can get a ticket for the submarine at Loch Ness, you have to take the first photo (Nessie loops) back to Mews. Then you can return and play darts against the other 2 players to win a sub ticket. Once you have the submarine photo, take it back to the Pub (taking it to Mews is no help at all).
You get the submarine ticket from the other two players in the pub, by winning at darts. Take the picture from the submarine back to the pub, where you find it is part of a movie prop. But the first dart player angrily returns and wants a rematch. Beat him to get the pennywhistle (from the bartender, not the sore loser).
You get the pennywhistle after winning your third game of darts at the pub. The first time, you get a rowboat ticket and take the "humps" photo back to Mews. The second time, you win a submarine ticket and get a photo that turns out to be a movie prop. When you beat the original darts player again, he is a poor loser but the bartender gives you the pennywhistle.
Go back to the pub and verse another player at darts.
You get the submarine ticket at the Pub on your second visit to Loch Ness. On the first visit, beating the player at darts gets you the rowboat ticket, but when you return the photo to Mews, it turns out to be less than convincing. When you return to Loch Ness, play the other player to get a submarine ticket, and dive to photograph a likely sea creature on the bottom of the Loch. Return to the Pub with the underwater photo.
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).