Continuity mistake: Early in the movie, the kids go moto-surfing and the jeep they are riding in changes from having a door to not having a door.
Other mistake: They live in Los Angeles. When they left to go to Patusan, the scene showed a map and a toy ship with someone's hand guiding the ship along. On the ship they came from the Atlantic, through the Panama Canal, to the Pacific then onto Patusan. How did they start from the Atlantic when they lived in Los Angeles?