For the next three days they threaded their way, under sail or paddle, among such numberless keys and through such a maze of narrow channels, that it seemed to Worth as though they were entangled in a labyrinth from which they would never be able to extricate themselves. Whenever a long sand-spit or reef shot out from the north side of one key, a similar obstruction was certain to be found on the south end of the next one. Thus their course was a perpetual zigzag, and a fair wind on one stretch would be dead ahead on the next. Now they slid through channels so narrow that the dense mangroves on either side brushed their decks, and then they would be confronted by a coral reef that seemed to extend unbrokenly in both directions as far as the eye could reach. Worth would make up his mind that there was nothing to do but get out and drag the canoes over it, when suddenly the _Psyche_, which was always in the lead, would dash directly at the obstacle, and skim through one of the narrow cuts with which all these reefs abound.