Plot hole: A tsunami has supposedly just hit the island, yet the trees and plants (and a 500 year old treasure chest) are undamaged.
Plot hole: The day after the plane crash-lands on the island, we see an aircraft carrier at sea and a squadron of heavily armed Marines climbing on board a Chinook helicopter. Someone is heard saying that they picked up a mayday from the plane before it went down, and the Marines are on their way to save the people on the island. Why did the Marines wait until the next day to go rescue the people? And if it's a rescue mission, why are they in full battle gear and carrying so many guns, since nothing was mentioned about the bad guys being on the island? These questions are moot since the Marines never arrive and no mention is ever made of them or the rescue mission again.
Plot hole: When the plane is crash landing in the storm and Nicolette Sheridan is calling for 'mayday', they can't get through to anyone because of the weather. The next day, one of the characters claims they heard on the plane's radio (before they crashed) that there's a tsunami headed toward them. If the radio was out, how did they know about the tsunami?