Abbreviation | General Nautical Terminology | Light Characteristic | Nautical Topics | Navigation | Signals & Communication
Obscured Light Sector (Obscd)
An arc in which the light is not visible or is intentionally screened.
Signals & Communication
Signals and communication in the marine world are like a game of charades with the ocean as your stage. Picture a crew furiously waving flags screaming, “We’re out of snacks!” while another ship squints, trying to decode whether that’s a distress call or just terrible semaphore skills. Horns blast at decibels high enough to wake Poseidon, with meanings ranging from “I’m turning left” to “Move it or lose it!” And let’s not forget Morse code—nothing says “urgent message” like blinking a flashlight at a seagull for hours. Meanwhile, the VHF radio crackles with static and a dozen accents yelling about the weather, leaving everyone more confused than enlightened. It’s a symphony of organised chaos where somehow, miraculously, no one crashes into an iceberg. Usually.
-
-
Abbreviation | General Nautical Terminology | Light Characteristic | Nautical Topics | Navigation | Signals & Communication
Intensified Light Sector (Intens)
An arc in which the light is shown with greater luminous intensity than in adjacent sectors.
-
Abbreviation | General Nautical Terminology | Light Characteristic | Nautical Topics | Navigation | Signals & Communication
Unintensified Light Sector (Unintens)
An arc in which the light has less intensity than its intensified sector.
-
World Radiocommunication Conference
An International Telecommunication Union conference that reviews and revises the Radio Regulations. WRC decisions allocate spectrum and set international provisions affecting maritime, aeronautical, satellite and other radio services. Conferences are held periodically, and changes are implemented through the resulting treaty acts and national administrations.
-
Sky Wave
A radio wave returned toward Earth after refraction in the ionosphere. Sky-wave propagation allows HF and sometimes MF signals to travel far beyond the radio horizon. Range and reliability vary with frequency, time, season, solar activity and ionospheric disturbance.
-
Racon
A radar transponder that replies to a received radar pulse with a coded signal identifying its location.
-
Radio Regulations
The international treaty rules governing use of the radio-frequency spectrum and satellite orbits. Maintained through the International Telecommunication Union, they allocate frequencies and set technical and operating provisions, including maritime services. National administrations implement and enforce them through licensing and domestic requirements.
-
Line-of-sight Propagation
Radio propagation along a substantially direct path between transmitting and receiving antennas. Its practical range is limited by antenna heights, Earth curvature, obstructions and atmospheric refraction. VHF maritime communication is primarily line-of-sight, so raising an antenna can increase range.
-
Enhanced Group Calling
A satellite broadcast service that sends maritime safety information to selected groups or geographic areas. EGC is carried through recognised mobile-satellite services and includes services such as SafetyNET. Compatible GMDSS equipment receives messages according to programmed sea areas, coastal warning areas and message priorities.
-
EPIRB
An Emergency Position-Indicating Radio Beacon carried to alert search-and-rescue authorities after a maritime distress. A 406 MHz EPIRB transmits a coded identity through Cospas-Sarsat and may include GNSS position and a homing signal. It must be registered, correctly mounted, tested only by approved methods and kept within battery and hydrostatic-release service dates.
If you belive the Earth is flat, you're about to fall of the end...
If you belive the Earth is flat, you're about to fall of the end...
