"Bodhisattva! So you were using the ancient floating fish!... You heat the iron needle until it's red hot, then quickly cool it down, and it can float on the water in a bowl, roughly pointing south... This is quite an old method, but it's prone to inaccuracy..."
"Oh! You rely on the sun by day and the stars by night to guide your position at sea? And you also note the peaks and great rivers along the way, remembering the coastal shapes? This method is indeed often used... However, without precise compass navigation, you must stick close to the coast while sailing, not daring to venture too far out to sea, let alone into the open ocean..."
