What radio equipment do you know?

A shipboard radio station includes all the transmitting and receiving equipment installed aboard a ship for communicating with other vessels, marine rescue groups and to receive navigational warnings and weather updates.

The marine radio equipment may be used aboard a ship:

· VHF Radiotelephone (156-162 MHz) - Used for voice communications with other ships and coast stations over short distances.

· Radar - Used for navigating, direction-finding, locating positions, and ship traffic control.

· EPIRB - Emergency Position Indicating Radio Beacons, or EPIRBs, are used when a ship is in distress, to emit a radio signal marking the ship's location. Extreme care must be taken to prevent inadvertent activation and batteries should be replaced prior to expiration date.

· Single sideband Radiotelephone (2-27.5 MHz) - Used to communicate over medium and long distances (hundreds, sometime thousands of nautical miles).

· Satellite Radio - Used to communicate by means of voice, data or direct printing via satellites.

· Radiotelegraph - Used to communicate by means of Morse code facsimile or narrow-band direct-printing.

· Survival Craft Radio - Used for survival purposes only from lifeboats and rafts.

· On Board Radio - These are low-powered radios used for internal voice communications on board a ship or for authorized short range communications directly associated with ship operations.

 

What is NAVTEX?/ What we need NAVTEX for? / Can some other information be taken from NAVTEX?

NAVTEX (Navigational Telex) is an international automated medium frequency direct-printing service for delivery of navigational warnings, meteorological warnings, ice reports, search & rescue information, piracy warnings, meteorological forecasts, weather actuals, pilot service messages, AIS messages.

NAVTEX is obligatory for Safety of Life at Sea (SOLAS) convention vessels, including some training yachts.

 

How does GPS work?

The Global Positioning System (GPS) is a network of about 30 satellites orbiting the Earth at an altitude of 20,000 km. The system was originally developed by the US government for military navigation but now anyone with a GPS device, be it a SatNav, mobile phone or handheld GPS unit, can receive the radio signals that the satellites broadcast. GPS works in any weather conditions, anywhere in the world, 24 hours a day.

GPS satellites circle the earth twice a day in a very precise orbit and transmit signal information to earth. GPS receivers take this information and use triangulation to calculate the user’s exact location. Essentially, the GPS receiver compares the time a signal was transmitted by a satellite with the time it was received. The time difference tells the GPS receiver how far away the satellite is. Now, with distance measurements from a few more satellites, the receiver can determine the user’s position and display it on the unit’s electronic map.

A GPS receiver must be locked on to the signal of at least three satellites to calculate a 2D position (latitude and longitude) and track movement. With four or more satellites in view, the receiver can determine the user’s 3D position (latitude, longitude and altitude). Once the user’s position has been determined, the GPS unit can calculate other information, such as speed, bearing, track, trip distance, distance to destination, sunrise and sunset time and more.

 

Do you know what equipment should be exhibited in daytime?

Day shapes should be exhibited in daytime. These signals are shown by day in all weathers on vessels to denote certain activities in which they are engaged. In restricted visibility, the appropriate lights should also be displayed by day.

The shapes are: cone, ball, cylinder, diamond.

 

What are Admiralty charts?

Admiralty charts are nautical charts issued by the United Kingdom Hydrographic Office. Over 3,000 charts are available and cover virtually the entire world in various levels of detail depending on the density of traffic and hazards. Large-scale charts often cover approaches and entrances to harbours, medium-scale charts cover heavily used coastal areas, and small-scale charts are for navigation in more open areas.

Charts include: depths (chart datum), coastline, bouyage, land and underwater contour lines, seabed composition (for anchoring), hazards, tidal information ("tidal diamonds"), prominent land features (e.g. church towers), traffic separation schemes, RF direction finding information, lights, and in short anything which could assist navigation.

 

Helm orders

1. Whose order should you follow first in case when a pilot and a master give youdifferent orders simultaneously?

Maritime pilot performs one of the most crucial tasks of navigating the ship through some of the most difficult navigational areas. He is the member of bridge team and his duty is to assist the Master by offering appropriate advice during the ship's passage. I must follow Master’s order as he is the Head of bridge team.

The International STCW Code specifies that the presence on board of a pilot does not relieve the Master from his duties and obligations for the safety of the ship.