Ingles Maritimo

Marine VHF radio is installed on all large ships and most seagoing small craft. It is also used, with slightly different regulation, on rivers and lakes. It is used for a wide variety of purposes, including summoning rescue services and communicating with harbours, locks, bridges and marinas, and operates in the very high frequency (VHF) range, between 156 and 162.025 MHz. Although it is widely used for collision avoidance, its use for that purpose is contentious and is strongly discouraged by some countries, including the UK.

A marine VHF set is a combined transmitter and receiver and only operates on standard, international frequencies known as channels. Channel 16(156.8 MHz) is the international calling and distress channel. Channel 9 can also be used in some places as a secondary call and distress channel. Transmission power ranges between 1 and 25 watts, giving a maximum range of up to about 60 nautical miles (111 km) between aerials mounted on tall ships and hills, and 5 nautical miles (9 km; 6 mi) between aerials mounted on small boats at sea level. Frequency modulation (FM) is used, with vertical polarization, meaning that antennas have to be vertical in order to have good reception.

AIS

The Automatic Identification System (AIS) is an automatic tracking system used on ships and by vessel traffic services (VTS) for identifying and locating vessels by electronically exchanging data with other nearby ships and AIS Base stations. AIS information supplements marine radar, which continues to be the primary method of collision avoidance for water transport.

Information provided by AIS equipment, such as unique identification, position, course, and speed, can be displayed on a screen or an ECDIS. AIS is intended to assist a vessel's watch standing officers and allow maritime authorities to track and monitor vessel movements. AIS integrates a standardized VHF transceiver with a positioning system such as a LORAN-C or GPS receiver, with other electronic navigation sensors, such as a gyrocompass or rate of turn indicator. Vessels fitted with AIS transceivers and transponders can be tracked by AIS base stations located along coast lines or, when out of range of terrestrial networks, through a growing number of satellites that are fitted with special AIS receivers.

Marine Radar

Marine radars are x-band or s-band radar to provide bearing and distance of ships and land targets in vicinity from own ship (radar scanner) for collision avoidance and navigation at sea.

Radar is a vital component for safety at sea and near the shore. Captains need to be able to maneuver theirs ships within feet in the worst of conditions and to be able to navigate "blind". This means inside a dark room with no visibility they need to safely navigate their way through waters in the worst of weather. Radars are rarely used alone in a marine setting.

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