This will probably be called a loony theory, but here it is. I believe that Bayle Domon has an angreal on his ship. In The Great Hunt, "Leavetakings", Domon is going through the things he has hidden in his secret cubbyhole. He had many strange things in there, including a light stick, a seal on the Dark One's prison, and i believe an angreal. His angreal was described as "...a small, age dark ivory carving of a man holding a sword. The fellow who sold it claimed that if you held it long enough you started to feel warm. Domon never had, and neither had any of the crew he let hold it, but it was old, and that was enough for Domon." As you can see this bears a resemblance between Rand's angreal, described in "Out of the Stone" in The Shadow Rising as, "...a carving of shiny dark green stone that fit easily into his hand, a round-faced round-bodied man sitting cross-legged with a sword across his knees." Rand also said that as soon as he picked the figure up,he knew it was an angreal. This could be why the fellow that sold the carving to Doman said it made you feel warm after a while. The fellow would have been able to channel, though most likely not aware of it, and been able to sense something about the carving. And because Doman and his crew cannot channel they couldn't feel anything about it.