The tidal phenomenon refers to the seawater in celestial bodies (mainly the moon and the sun), the cyclical movement of the tidal force under customary sea vertical direction fluctuation known as tidal, called the trend of seawater flow in the horizontal direction. Is a natural phenomenon of the coastal areas, The Ancient said daytime Hohai gushing "boom", the evening called "Xi", collectively referred to as "tidal".
On the shipping side, some waterways and harbor are required to sailing around the max tide into and out of Hong Kong; in the military, sometimes in order to select the favorable landing place and time, it must be taken into account and master the tidal situation; In terms of production, coastal fisheries, aquaculture aquaculture, agriculture, salt, resource development, port construction, surveying, environmental protection and tidal power generation, must master the tidal changes in the law. Tide Tables for these services.
Navigation, tidal information is very important, especially some of the large, deeper-draft ship rely unberthing often requires Tide missed the tide not dock or unberthing can only wait for the next tide.
This application will collect to release the tidal forecast information of various major ports around the world, to learn anytime, anywhere convenience captain, first mate, and port management scheduling, diversion port tidal state, reasonable arrangements for the operation of the vessel time.

潮汐现象是指海水在天体（主要是月球和太阳）引潮力作用下所产生的周期性运动，习惯上把海面垂直方向涨落称为潮汐，而海水在水平方向的流动称为潮流。是沿海地区的一种自然现象，古代称白天的河海涌水为“潮”，晚上的称为“汐”，合称为“潮汐”。
在航运方面，有些水道和港湾须在高潮前后才能航行和进出港；在军事方面，有时为了选择有利的登陆地点和时间，就必须考虑和掌握潮汐的情况；在生产方面，沿海的渔业、水产养殖业、农业、盐业、资源开发、港口工程建设、测量、环境保护和潮汐发电等，都要掌握潮汐变化的规律。潮汐表就是为这些方面服务的。
在航海中，潮汐信息的应用非常重要，特别是一些吃水较深的大型船靠离泊的时候，常常需要赶潮，错过了潮水无法靠泊或者离泊，只能等下一次的潮水。
本应用将收集发布全球各个主要港口的潮汐预报信息，方便船长、大副和港口管理调度、引水等人员随时随地了解港口潮汐状态，合理安排船舶作业时间。