You first need to look through the painter's telescope and see the map on the far right (the seals and the seesaw rock). Get the jet ski keys by recovering Cap'n Salty's lost lobster trap.
Catch the old photo blowing in the wind by the lighthouse, and swap it for diving gear at the Say Cheese photo shop. Dive at Puffin Point and recover the trap, and Cap'n salty gives you a lobster and the jet ski keys.
You do not play as Big Nate. He accompanies you around most of the island, and races you on the jet skis.
Climb the lighthouse and ask the artist if you can look. (Once you see the seals on Seal-Saw Island, you can race Nate there on the jet skis.)
you have to get the lobster cage from the oyster beds in puffin point after you get the scuba gear. Sorry that it's so long.
You will race with Nate on the jet skis (one of the three mini-games) to the island where the map is stuck under a rock with seals on it. Get the keys by recovering Cap'n Salty's lost lobster trap. Climb the lighthouse and look through the telescope to see the "seal-saw" island to the far right. Until you look, you can't use the jet ski. (See related questions)
You can see it from the telescope on top of the lighthouse : it is on a seal island just offshore. (to the far right) To get the map, you will need to race Nate on the jet skis. (Move the seals to one side of the seesaw rock to get the map out.) (see related question)
There is a map for the time capsule. You have to beat Nate in a race on the jet skis. Get the keys from Captain Salty by going under water to get his trap. Once you beat big Nate you'll come to an island with a piece of paper under it there will be seal on it push both of them to the left then pull the piece of paper which is the map to the time capsule.
It is on top of the lighthouse. You can see Seal Island from there. But you can't go there until you recover the lobster trap for Cap'n Salty, who will give you the keys to his Jet Skis.
You can see it from the telescope on top of the lighthouse : it is on a seal island just offshore. (to the far right) To get the map, you will need to race Nate on the jet skis (see related question). (Move the seals to one side of the seesaw rock to get the map out.) (see related questions)
The seal island is to the right of the lighthouse, and you can get there by racing Nate on the jet skis.Catch the photo blowing in the air by the lighthouse, and swap it for diving gear at the Photo Shop. Use the gear at the lighthouse to recover Cap'n Salty's lobster trap, and he will give you the keys to the jet skis. You will have to go to the top of the lighthouse and look through the telescope to see the island.
The diving mini-game is the way to get this. You will need an old photograph that is blowing in the wind near the lighthouse : swap it for scuba gear at the "Say Cheese" photo shop. Then dive for the old sailor's lost lobster trap. He will let you keep a lobster and give you the key to the jet ski. Use the telescope on the lighthouse, then race Nate on the jet skis, going out to the seals' island for the map there.
The old sailor (Cap'n Salty) has lost his favorite lobster trap at Puffin Point, past the lighthouse. If you recover it for him, he will give you a lobster, and the keys to the jet skis for you and Nate. To get the diving suit, catch the photo blowing in the wind by the lighthouse, and take it to the Say Cheese photo shop. The owner will give you his scuba gear for it. Put it on and dive past the bubbles to retrieve the trap.
You get the keys to the jet ski when you recover Cap'n Salty's lost lobster trap. Catch the old photo blowing in the air at the lighthouse. Trade it for scuba gear at the Say Cheese photo shop. Dive to get the lobster trap at Puffin Point. Cap'n Salty will give you the jet ski keys. Look through the telescope atop the lighthouse to see your destination : the Seal Island seesaw. Now you can race Nate there to recover the map