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Category Archives: Navigation

Ice on the Sea

Ice is found at high latitudes in both hemispheres i.e. Northern Hemisphere (Artic) and Southern Hemisphere (Antarctic) regions. They differ greatly because of their physical dissimilarities. The Artic Basin is an area of ocean, which is covered up a thin shell of ice about 3.5

Weather Reporting System

Efficient weather service to shipping depends on the timely location and accurate tracking of weather systems over the open sea, which covers three-quarters of the surface of the earth. Weather is a very important factor in determination of the passage and safe completion. Need for

Anchoring glossary of Terms and abbreviations

  Aframax (tanker) An AFRA (Average Freight Rate Assessment)max is a medium-sized oil tanker which ranges in size between 80,000 and 119,999 deadweight tonnes. Aframax tankers have an average cargo carrying capacity of 750,000 barrels. Anchor Holding Power The holding power of an anchor is

Anchor swinging circle

Monitoring the drag with swing circle A ship at anchor will swing around the anchored position in the wind. A ship at anchor will swing around the anchored position in the wind. It is also recommended to draw a small circle on the chart around

Gyro Compass

The ships main gyro compass gives the heading of the vessel with respect to true north. A Gyro compass is a form of gyroscope, used widely on ships employing an electrically powered, fast spinning gyroscope wheel and frictional forces among other factors utilizing the basic

Magnetic Compass

As per Chapter V of SOLAS 74, as amended, a magnetic compass is a compulsory part of ship borne navigational equipment. This is in addition to the gyro compass & suitably placed repeaters on the ship. This is so primary because of the reliable dependence

course recorder

Course Recorder

It records the Gyro course steered by the vessel continuously against a time scale. The record is considered as useful and vital evidence in case of any accident. The equipment is set at the commencement of a voyage with correct time and then switched on

automatic identiciation system

Automatic Identification System

AIS is a system that transmits vessel position, course and speed via a VHF radio channel to all ships within range (typically up to 30 miles). It also receives similar information from other AIS equipped vessels within range. Automatic identification system (AIS) is fitted aboard

parallel indexing

Parallel Indexing

Parallel indexing is an effective way of monitoring a vessels progress along a preselected track using a radar. As a vessel moves on its chosen heading, fixed objects in its radar vicinity appear to be moving in a reciprocal direction to this motion. This technique

azimuth circle

Azimuth Mirror

A compass is equipment which is used to find direction while at sea. A compass tells the direction in which the ship is going or the direction of any other object. An azimuth mirror is used in conjunction with a compass. This device enables the