On August 13, 1592, the Korean fleet sailing from the Miruk Island at Dangpo received local intelligence that a large Japanese fleet was nearby. The following morning, the Korean fleet spotted the Japanese fleet of 82 vessels anchored in the straits of Gyeonnaeryang. Because of the narrowness of the strait and the hazard posed by the underwater rocks, Admiral Yi sent six ships to lure out 63 Japanese vessels into the wider sea, and the Japanese fleet followed. There the Japanese fleet was surrounded by the Korean fleet in a semicircular formation called "crane wing" (학익진) by Admiral Yi. With at least three turtle ships (two of which were newly completed) spearheading the clash against the Japanese fleet, the Korean vessels fired volleys of cannonballs into the Japanese formation. Then the Korean ships engaged in a free-for-all battle with the Japanese ships, maintaining enough distance to prevent the Japanese from boarding; Admiral Yi permitted melee combats only against severely damaged Japanese ships.