The captain charted this area out and it's quite safe to sail in it.船长在海图上标出了这个区域，在这一区域里航行是相当安全的。These seas have been well charted.这些海域的海图已经相当精准。The captain located the ship's position on the chart.船长在海图上确定了船只所处的位置。The ship had drifted into uncharted waters.船漂到了海图上未标明的海域。