The reports to the emperor made mention of Taiwan and Penghu's geographic and strategic importance: "Looking at all of Taiwan's ports, from Tachia south to Fengshan, the sand banks are vast, and warships cannot approach the shore.
摺中提到台澎的地理位置及戰略地位，「查全台各海口，大甲以南至鳳山，沙線遠闊，兵船不能攏岸。