My take on the lyrics - it's probably about the first pilgrims leaving England (or Europe in general) and heading for North America, running away from all the troubles in their old life. The talisman itself appears to be a magical compass or possibly a "lucky charm" of some sort, pointing them exactly where they need to go. Of course, most of them don't make the trip, including the storyteller who clings on to life just to see the shores of the New world. It appears that he dies of scurvy - "those that didn't die in storms, the scurcy rest did slaughter".
A cringeworty line in the song - "The winds lash the sails but the ropes keep them tight". Seems to me like a moment of no inspiration, they needed a line and couldn't think of anything that made a bit more sense.