Coast Guard Navigational Equipment: GPS

• Navigational Equipment is important for those in training for the Coast Guard

GPS

• The Global Positioning System (GPS) is a space-based satellite navigation system.
• GPS provides location and time information in all weather conditions, anywhere on or near the Earth that has an unobstructed line of sight to four or more GPS satellites.
• GPS provides critical capabilities to military, civil, and commercial users around the world.
• The United States government maintains GPS
• Anybody with a GPS receiver can freely access the information.
• The GPS is a satellite-based navigation system.
• GPS consists of a network of 24 satellites placed into orbit by the U.S. Department of Defense.
• GPS was originally intended for military applications
• In the 1980s, the government made GPS available for civilian use.
• GPS works in any weather conditions, anywhere in the world, 24 hours a day.
• No subscription fees or setup charges are required to use GPS.

RADAR

• Seagoing vessels depend on S-band and X-band frequency radar systems for navigation.
• Radar systems detect targets and display information on the screen, such as the distance of the ship from land, floating objects (islands, rocks, icebergs, etc.), other vessels, and obstacles to avoid collisions.
• A rotating antenna discovers the surrounding area of the ship.
• The main nonmilitary use of radar is to avoid collisions.
• Using radar, the navigator of a ship can see other vessels irrespective of light conditions.
• Radar makes it possible to proceed safely in thick fog, whereas without radar it would be necessary to heave to or anchor.
• Collision avoidance requires great skill in interpretation, as the radar picture is imperfect.
• It’s not easy to see the direction in which other vessels are traveling.
• Navigators must make particularly bold alterations of course to ensure that other navigators do not misinterpret them.
• Marine radars are X band or S band radars on ships.
• They are used to detect other ships and land hazards, to provide bearing and distance for collision avoidance and navigation at sea.
• The X-band operates at 9 GHz and provides a sharper image and better resolution, making it ideal for use in clear weather conditions.
• The S-band, on the other hand, operates at 3GHz and is better suited for use in fog, rain, or other adverse weather conditions.

ARPA

• An automatic radar plotting aid displays the location of the ship and other vessels nearby.
• The radar displays the location of nearby ships and selects a course for the ship, avoiding collisions.
• This navigation equipment on the bridge constantly monitors the ship's surroundings.
• It automatically determines the number of targets, ships, boats, stationary or floating objects etc., and plots their speed and course accordingly.
• It presents them as vectors on the display screen and constantly updates the parameters with each rotation of the antenna.
• It calculates their closest points of approach to the ship, as well as the time before this happens.

ECDIS

• ECDIS (Electronic Chart Display and Information System) provides continuous position and navigational safety information.
• The system generates audible or visual alarms when the vessel is in proximity to navigational hazards.
• Military versions of ECDIS are known as WECDIS
• The primary function of the ECDIS is to contribute to safe navigation.
• ECDIS, with adequate backup arrangements, may be accepted as complying with the up-to-date charts required by regulation V/20 of the 1974 SOLAS Convention.
• ECDIS is a specialized electronic navigation system used by ships and vessels for voyage planning, route monitoring, and collision avoidance.
• ECDIS replaces traditional paper charts and offers a digital, interactive, and dynamic display of navigational charts.

Gyro Compass

• Gyro compasses are used for finding the right direction.
• Unlike magnetic compasses, gyro compasses are not hampered by an external magnetic field.
• Used to find the correct North Position, which is also the earth's rotational axis.
• Provides a stable directional source.
• Gyrocompass repeater system must be present in the steering platform for emergency steering.

Magnetic Compass

• Magnetic compasses work in conjunction with the magnetic field of the earth.
• They are the essential means of the direction indicating device.
• Used to get a planned course for the voyage.
• Ship navigation equipment is usually fitted at the center line of the ship on the monkey island.
• A transmitting magnetic type compass is fitted so that the output can be displayed in the bridge panel.

Echo Sounder

• An echo sounder sends sound wave pulses from a transducer usually located on the bottom of a ship/boat's hull.
• Pulses travel through the water, hit submerged objects such as the ocean floor, wrecks, and large schools of fish, bounce off, and return upwards to the transducer.
• The echo sounder calculates the time it takes for the pulses to return, and indicates the distance from the boat to ocean's bottom.
• Echo sounders used on big ships to assess the water's depth are fathometers, because commercial vessels use fathoms as their unit of water

Automatic Identification System

• AIS is a navigation system that pinpoints the location and other navigational statistics of ships.
• AlS uses VHF radio channels as transmitters and receivers.
• Transmits and receives messages between ships to fulfill a lot of responsibilities.
• All passengers' vessels and commercial ships over 299 Gross Tonnage (GT) sailing internationally must carry a Class A AIS transponder, as per the regulation enforced by The International Maritime Organization (IMO).

Autopilot

• Autopilot is considered one of the most effective bridge navigation aids.
• It helps the human operator steer the vessel by holding the steering in autopilot mode.
• Allows focusing on the broad aspects of the operation.
• It is a combination of hydraulic, mechanical, and electrical systems.
• Controls the ship's steering system from a remote location, the navigational bridge.

Speed and Distance Log Device

• Bridge equipment is used to measure the speed and the distance traveled by a ship from a set point.
• ETA of the ship is adjusted or given to the port authority and agent.

Doppler Speed Log

• Doppler log is based on the principle of Doppler shift in frequency measurement.
• Doppler logs measure the apparent change in frequency received when the distance between source and observer is changing due to the motion of either source or observer or both.
• In Doppler logs, an observer is moving with a source of sound towards a reflecting plane, then measures the received frequency.
• Determines the the speed of the vessel by measuring the received frequency, knowing the value of transmitted frequency, and the velocity of sound in seawater.

Satellite Speed Log

• Most satellite speed logs use GPS (Global Positioning System) technology to determine a ship's location and speed.
• GPS works by triangulating signals from multiple satellites to pinpoint a ship's exact location.
• This information calculates the ship's speed and direction of travel.

Impeller Speed Log

• Impeller logs used on ships to measure speed and distance traveled.
• The impeller log has a rotating impeller fitted inside a retractable tube on the ship's bottom

Rudder Angle Indicator

• Provides the angle of the rudder.
• The display is provided on the navigation bridge equipment console.
• Ships navigation officers controls the rate of turn and rudder angle of the ship
• Indication is also provided in the bridge wing and engine control room.

Rate of Turn Indicator

• Navigational tool indicates how fast the ship is turning at a steady rate, useful during pilotage and maneuvering.
• Normally shown as a number of degrees turned.
• The rate ship is turning is measured in degrees per minute.
• This tool assists a coxswain in steering a course safely.

Ships Master Clock

• Marine Master Clock is the ideal solution for the distribution of both Local and UTC time on board ships.
• The Master Clock is equipped with several outputs and inputs for the control of Slave Clocks.
• The Master Clocks distributes the time to computers and other equipment needing the correct

Aneroid Barometer

• Aneroid barometers are instrumental devices used to measure atmospheric pressure.
• Helpful in the maritime industry for several reasons.
• Primary function is to predict weather changes

MF/HF/VHF Radios

• Marine radio was the first commercial application of radio technology, allowing ships to keep in touch with shore and other ships.
• Helps ships send out a distress call for rescue in case of emergency.
• Units may be Fixed Mounted VHF or Handheld VHF.
• Digital Selective Calling (DSC) is used with VHF, MF, and HF radio systems to establish communications with (call) ships or coast stations.

GMDSS

• The GMDSS (Global Maritime Distress and Safety System) is an internationally recognized distress and radio communication safety system.
• Automates ship-to-shore and ship-to-ship communications.
• Uses satellites and/or terrestrial radio systems with digital selective calling technology.
• GMDSS ships must carry a 406 MHz EPIRB, a VHF radio capable of transmitting and receiving DSC and radiotelephony, a NAVTEX receiver, a SART, backup power systems to enable emergency communications if primary power fails and two-way VHF portable radios

GMDSS Areas

• Al:VHF equipment / S-EPIRB or VHF EPIRB / MSI receiver
• A2: VHF and MF equipment / S-EPIRB / MSI receiver
• A3: VHF, MF and HF or satellite equipment / S-EPIRB / MSI receiver
• A4: VHF, MF and HF equipment / 406 MHz S-EPIRB / MSI receiver

Voyage Data Recorder

• A VDR or voyage data recorder is a crucial instrument among the ship navigation equipment.
• Installed on a ship to continuously record vital information related to the operation of a vessel.
• Contains a voice recording system for at least the last 12 hours.
• Recording is recovered and made use of for investigation in events of accidents.
• Similar to a "black box" installed on an

Navigational Lights

• All boats, whether big or small, are required to have night lights as a part of the navigation systems.
• Introduced in 1838 by the United States and then followed by the United Kingdom in 1849.
• The International Maritime Conference was established by the United States in 1889 to establish proper guidelines to prevent marine accidents.
• These rules were officially adopted internationally in 1897.
• Critical navigation equipment for sailing in high seas as it enables self vessel being clearly visible to other ships in the vicinity.

Ship Horn

• A ship's horn is known as a whistle, and is generally provided in duplicate.
• One is driven by air and the other is electrically operated.
• The whistle should be both manually and electrically operational from the bridge.
• Instruments used in difficult navigation like bad weather, fog, poor visibility, high traffic etc helps in alerting the nearby vessels.
• During an emergency, the horn alerts the ship's crew and other nearby vessels.

Signaling Lamp

• Light-signaling devices are used for emergency signaling in the night time, and can also be used during the day.
• The energy source for the lamp is not solely dependent on the ship's main power supply.
• The lamp enclosure should be weather proof and seawater-proof material.

Day Shapes

• Used with boats
• Day shapes or day markers are mast head signals made up of geometric shapes.
• Signals convey the status of a vessel on navigable waters during daylight hours.
• The four basic shapes of the markers are ball, cylinder, cone, and diamond.
• They are used alone or in combination to provide a range of status updates visible during the day and intend to mimic the navigation light requirement for nightfall or low visibility.
• Deployed from sunrise to sunset and are typically hung from a mast for easy visibility from a distance.