The first humpback whale of the season has been spotted off Kauai.Crew aboard a boat with a Kauai Charter saw the whale surface about a mile off the west side of the island. They snapped a photo of the whale before it slipped back underwater. The National Oceanic and Atmospheric Administration estimates that as many as 15,000 humpback whales visit Hawaii every winter. They come to the islands to breed, calve and nurse their young. According to NOAA, the first humpback whale wasn't spotted last year until Oct. 4 and Monday's sighting is unusually early in the season. February and March are considered the peak of the whale watching season. Sometimes, the whales stay until May before traveling back to Alaska.