islands have either a lagoon or a pond; only East Caicos lacks one. On 14 October, Columbus made a boat trip to "the other part, which was the eastern part" of Guanahani. Therefore, he went the length of the island in a north-northeast direction. This is possible only at Plana Cays, Conception and Egg, and to a very minor extent at Samana Cay. Columbus noticed a reef that completely surrounded the island. All proposed islands have a reef, but the ones on Cat and Watling's do not completely surround the island. Between the reef and the island was a harbor "large enough to store all ships of Christendom." This could easily have been an exaggeration. The harbor on Egg is definitely too small, although it is fairly appropriate for the impressive harbor at the neighboring islet of Royal Island, which could have been considered part of the same larger island he named "San Salvador" (the other "part, which is the eastern part"). Columbus went on land and saw "a piece of land, that looked like an island, but actually wasn't one." This is difficult to track, because it may have become a real island in the past 500 years. Number of islands One question in dispute is whether Guanahani was one island or more than one. Evidence is said to be inconclusive. Columbus never says specifically that Guanahani consisted of more than one island, something which is surely worth noting. But he does say that Guanahani had "another part, which is the eastern part"; and to explore that eastern part, he used a boat rather than walking, which may be significant. On reproductions of the map by Juan de la Cosa, who was with Columbus, Guanahani looks to some researchers like a string of small islands. Transatlantic track The first way to locate Guanahani is to follow the distances and directions Columbus gave in his log. This procedure is difficult because of the uncertainties in knowing the length of Columbus' league, the speed and direction of ocean currents, and the exact direction his magnetic compass would have pointed in 1492. John McElroy was one of the first to attempt this in 1941, using a speculative magnetic chart for the year 1500 and currents from pilot charts. His vast overrun in distance was corrected by a fudge factor, leaving his endpoint in the vicinity of Watling's Island. This result was substantially