There was confusion in the press after the fatal flight. "Putnam never said that Earhart had a portable life raft or an emergency radio. The Itasca got that mistaken impression early in the search from a badly-worded and misinterpreted exchange of messages with Coast guard headquarters in San Francisco. Several days later the confusion was cleared up" (Gillespie, Forum, 2004-11-06).
Probable source of the confusion
From Rick Jones:
Corbis has an image of Earhart inflating a life raft. Its original caption was wrong and may be a contributing factor to the misunderstanding about having the raft on the world flight. It lists the date taken as July 1937 and the caption reads: "Amelia Earhart is shown here as she inflated the tiny rubber life raft that was part of the equipment of her 'flying laboratory,' during preparation for her round the world flight. With the plane downed somewhere in the Pacific, probably adjacent to Howland Island, this raft may have meant the difference between life and death for the aviatrix and her navigator, Fred Noonan."
Another caption to the same picture reads: "26 Jan 1935 --- 'Free Air' as long as she can stay aloft in trans-ocean flying for Amelia Earhart, but if forced down she was prepared for the worst with this tiny rubber lifeboat. The famed aviatrix demonstrated it before taking off for the East from Los Angeles 'to see it would have worked.' Inflated by a tiny cylinder, the boat has to be kept pumped up by hand. --- Image by © Bettmann/CORBIS." The airplane in the photo, I believe, is the Vega.
Later confusion was created when a deflated life raft that washed up on Hawaii Island's northwest tip was thought to be from the Earhart Electra.