Category Archives :Maritime knowledge

There have been a significant number of collisions where subsequent investigation has found that at some stage before impact, one or both parties were using VHF radio in an attempt to avoid collision. The use of VHF radio in these circumstances is not always helpful and may even prove to be dangerous.  ...

When getting your vessel ready for use in the summer months it is important to make sure you kit it out with the right gear. One piece of gear every vessel should have is a reliable marine radio. These radios are available as both a portable handheld and a fixed mount solution. First, what is a handheld VHF? A handheld VHF is as it sounds, a VHF radio that fits in your hand.  ...

Because radio is now common among commercial vessels on the larger freight waterways, there is a tendency to rely on it as a means of ascertaining the locations of other vessels. If they hear you on the radio, they will know where you are likely to be and can call you to warn of their approach, if necessary. It is also commonly used on larger waterways, replacing flag signals and to some extent sound signals,  ...

An MMSI is a unique nine digit number that is entered into certain marine radio communications equipment. When using this equipment to send a distress alert, or to indicate some other emergency, the number assists emergency services to identify you and/or your vessel. Since marine VHF transceivers now operate under a class licence, there is no requirement for an official call sign and maritime ship station license,  ...

So what is an antenna exactly? It is a device that takes an oscillating electric current and radiates that energy in the form of electromagnetic radiation and vice versa; depending on whether you are receiving or transmitting. More simply, it converts electric power into radio waves or radio waves into electric power. Understanding the important characteristics of the marine VHF antenna will allow you select the right antenna to best fit your vessel and your specific needs.  ...

In the United States, the National Telecommunications Administration (NTIA) provides MMSIs to federal users, and the Federal Communication Commission (FCC) provides MMSIs to everyone else.  NTIA is as Executive Branch agency under the Department of Commerce, and the FCC is an independent agency.  ...

Having a marine (VHF) radio aboard your boat can be a lifesaver.  VHF radios are the handiest and fastest way to contact other boaters or to ask for help on the water.  In an emergency, when you use a radio, anyone with a radio can hear you and can come to your aid, perhaps sooner than first responders.  Or you may be the boater who rescues someone because you heard their radio call.   ...

The low cost VHF Marine Radios, whether they are fixed or handheld, provides you with basic functionality. This means, that they will provide basic communications well, but will not likely to have additional features. The performance of the radio will be quite adequate and help keep you safe while on the water.  ...

The reach of a two-way radio is largely dependent on the output power of the radio. This is measured in watts. As an example, a typical fixed mount radio outputs at 25 watts and is good for a range of in excess of 50 km unobstructed. Handheld radios typically transmit at 5 to 6 watts and are therefore good for a range of 12 to 18 kms.  This is only a rough measure as other aspects affect the effective range of a VHF radio. The antenna type, design and length will have an effect on range.  ...

In an emergency, communication is vital and a marine radio is essential. Mobile telephones, although useful as a backup communications system, cannot replace a marine radio.  ...