1763년 대일통신사 사행록인 『계미수사록』은 이제까지 학계에는 거의 소개가 되지 않았던 자료로, 유일하게 통신사선 건조와 운항실태에 관한 기록이 수록되어 있다. 그 동안 통신사선 선체구조에 대한 기본자료로는 1708년 金慶門 등이 편찬한 『通文館志』 제5·6권과 1802년 사역원 당상역관 金健瑞 등이 편찬한 『증정교린지』가 이용되어 왔으나, 이들 기록도 통제영 통신사선 건조절목을 인용한 것임을 『계미수사록』을 통해서 추정할 수가 있으며, 이 자료는 이제까지 통신사선 건조에 있어서 미궁으로 남아있던 부분을 상당히 보완할 수가 있다.

‘Kyemisusarok’(계미수사록: the envoy mission account in 1763) is one of the newly disclosed diplomatic envoy`s account, relating to envoy visits to Japan, which were written in 1763. In this account, we can find out some mysterious matters regarding the building of envoy ships and a navigation system during the Yi Dynasty. Many new disclosures were obtained from this account. especially the building specifications and crew list of the ships, these being the most important records ever obtained, such information never having been seen in previous records and articles, excepting `Zeungjeongkyorinji`(增正交隣志 : diplomatic envoy records with Japan) edited by Kim Geun Se, a Japanese interpreter and published in 1802. Furthermore, we have learnt of some mistakes regarding the ship`s specification in `Zeungjeoungkyorinji` compared with the `Kyemisusarok`. The `Kyemisusarok` consist of 8 parts. 1) The building specification of the diplomatic mission fleet in 1763. 2) Building record, 3) Envoy record, 4) Diplomatic records after landing at Osaka, Japan, 5) Itinerary while at sea and on land in Japan, 6) Diplomatic document form for the courtesy visit, 7) Member lists of the diplomatic envoy and crew listings, and 8) Gift list for Bakufu(幕府). The items 1), 2) and 7) are the most important records, which have been seen for the previous cases, amongst these or others records. The Diplomatic envoy fleet to Japan was basically composed of 6 vessels, 3 ships for transportation of the envoy members, and 3 ships for their foods at the sea and the carrying of gift to Japan. Among the 6 ships, 4 ships were builded in Tongyoung, while the other 2 ships were built in Jwasuyoung, Busan. The main specification of the senior envoy ship named ‘Jeongsa-Kisun(正使 騎船)’ WRY was her length of about 30 meter, width of 9.5 meter, with a depth of 3.0 meter and deadweight of approximately 150 tons. This type of vessel compares favorably with the western ships of the `Schooner` type in the middle of the 18th century. During the period 1607 to 1811, diplomatic envoy fleets despatched from Korea to Japan 12 times in all, this was in order to promote diplomatic relationship between Korea and Japan. One envoy unit consists of about 500 persons: they left from Seoul to Busan on foot, Busan to Osaka by ship, and then Osaka to Tokyo on foot. For each visit sea transportation took about 2 months for a round voyage, and about 5 to 6 months for Land travel on the journey between Seoul to Tokyo. During the travelling in Japan, they experienced interchange with many Japanese people, even scholars. However, there had been many cultural exchanges in Japan with books, fine arts, medicines, music, acrobatics, etc. Thus Korea bestowed advanced cultures to Japan through these envoy visits and the envoy member`s activities. Many envoy members wrote various accounts relating to their travelling, both in the official reports and private diaries. But these lacked records on the envoy vessels, crew, the ship building records, and method of navigation. `Kyemisusarok` would now supply us with useful information about these facts.