Sea route - Kouro (English spelling)

Japanese: 航路 - こうろ（英語表記）sea route

A waterway is a route on which ships navigate. It can be broadly divided into navigational routes that focus on the safety and efficiency of ships, and shipping management routes that focus on the transportation of cargo and passengers.

[Fumihiko Kawamoto]

Navigational route

When undertaking a voyage, a safe and economical route is first selected, taking into consideration the purpose of the voyage, the condition of the ship, the influence of external forces such as weather and sea conditions, various agreements and recommendations, etc., and a course is then set along this route so that the ship will travel along it for a certain period of time or between two specific points. Therefore, a navigational route is a concept that is both land-based and direct.

During the age of sailing ships, which used wind as their power source, there were sailing routes that focused on utilizing external forces such as wind and ocean currents, but with the advent of the age of steamships, which could navigate against external forces to a certain extent, efficient and economical steamship routes that focused on shortening distances were adopted. There is no single such route if the departure and destination are the same; many are selected depending on the condition of the ship and the season, but several commonly used routes naturally emerge from the long-term experience of many ships. Among these, there are recommended routes that are recommended by the hydrographic departments of each country as safe and efficient routes based on various nautical documents and surveys.

Furthermore, in order to prevent accidents such as collisions and groundings in high-traffic areas near narrow channels and important ports where many ships' routes converge, there are "route designations" that are recommended to be followed by ships passing each other, such as designating separate routes for passing ships, with the aim of creating orderly traffic flow, and terms such as "passage route," "mutual traffic route," and "deep water route" are used here. Similar domestic laws include routes designated as applicable sea areas under the Maritime Traffic Safety Act, such as the Nakanose Passage and the Akashi Kaikyo Passage, and these are sometimes collectively referred to as designated routes or separate routes.

In addition, taking into account differences in route selection, position measurement, and navigation operations, terms such as port routes, coastal routes, near-shore routes, and ocean routes are used.

[Fumihiko Kawamoto]

Shipping routes

Depending on the type of ship operation, the most commonly used terms are regular route, irregular route, and tanker route, but in addition, depending on whether the route is only within the country or also extends abroad, it can also be called a domestic route, foreign route or international route, or a trilateral route, and depending on the destination or region, it can also be called a New York route, a European route, a circumnavigation route, etc.

There are also trunk routes, where large tankers or cargo ships transport goods to specific ports, and then transfer them to smaller coastal ships for transport to various locations; branch routes; remote island routes, which transport passengers and cargo to remote islands such as the Izu Seven Islands; and subsidized routes, which are operated with subsidies on routes that are less profitable.

In addition, in relation to the Ship Safety Act and the Ship's Officers and Small Vessel Operators Act, a ship's equipment and crew qualifications are differentiated according to the navigation area, and terms used in maritime management, such as ocean route, near-sea route, coastal route, and flat water route, are also used.

It is used in a variety of ways, making it an extremely difficult term that needs to be used appropriately depending on the time and situation.

[Fumihiko Kawamoto]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

Japanese:

船舶の航行する水路をいう。船舶の安全、能率運航に主眼を置いた航法上の航路と、貨物や旅客の運送に重点を置いた海運経営上の航路に大別できる。

［川本文彦］

航法上の航路

航海の実施にあたっては、まず航海の目的、自船の状況、気象・海象等の外力の影響、各種の協定や勧告などを考慮して、安全かつ経済的な航路が選定され、この航路に沿って、一定時間または特定の2地点間を船が進むように針路が定められる。したがって、航法上の航路とは、対地的かつ直航化された概念である。

　風を動力源とした帆船時代には、風系・海流系などの外力の利用に主眼を置いた帆船航路があり、ある程度は外力に逆らって航行できる汽船時代に入ると、距離の短縮に重点を置いた能率的・経済的な汽船航路が採用されるようになる。このような航路は、出発地と目的地が同じであればただ一つというわけではなく、船の状態、季節などによって数多く選定されるが、多くの船の長期にわたる経験からいくつかの常用航路が自然的に発生する。このうち各種の航海資料や調査に基づいて、安全かつ能率的な航路であるとして各国水路部等が推薦する推薦航路がある。

　さらに、多くの船の航路が集中する狭水道や重要港湾の近くで、交通密度の高い海域での衝突や座礁などの事故を防止するため、秩序ある交通流をつくりだす目的で、行き合い船の航路を分離して指定するなど、国際海事機関（IMO）によってこれに従うことを勧告されている「航路指定」があり、ここでは通航路、相互通航路、深水深航路などの用語が用いられている。類似の国内法では、海上交通安全法で適用海域を指定された航路、たとえば中の瀬航路、明石(あかし)海峡航路などがあり、これらを総称して指定航路、分離航路とよぶこともある。

　また航路選定や位置測定、航海実施上の差異に着目して、出入港航路、沿岸航路、近海航路、大洋航路などのことばが用いられる。

［川本文彦］