Author page: nautica

Introduction

Weather faxes provide the latest meteorological and oceanographic information available worldwide. They can be received with a Single Sideband Radio. The following key weather and sea charts are useful to mariners: • Surface charts • Sea state...

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Sea state analysis chart

The sea state analysis chart shows characteristics of sea waves and direction of movement. These observations are normally made a few hours before broadcast time. The combined sea heights are depicted in solid contours. The relative maxima or...

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Surface charts 1

Surface charts provide mariners with the principal tool for a basic understanding of the present and upcoming weather. Let’s have a closer look at surface charts, differentiating between the surface weather analysis and the surface weather...

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Surface charts 2

Here is an example of a 24 hr surface forecast chart. On this chart we can see the isobar lines, warm and cold fronts, the central pressure millibar values of synoptic scale lows and highs and their position in 24 hours. The 24 hour forecast...

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Introduction

The primary cause of restricted visibility is fog, heavy rain, or very rough seas. Haze or snow can also cause visibility to be restricted. Sailing in restricted visibility presents hazards, such as collision with another vessel or object, and...

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Precautions 1

The first thing to do when you notice approaching fog is to plot an accurate fix on the chart as soon as possible. If for any reason you cannot get an accurate fix, then rely on your Dead Reckoning or Estimated Position. Start sounding your...

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Precautions 2

Other steps to be taken in restricted visibility are: Post a lookout for lights and signals of other vessels well forward, away from the noise of the engine. If the boat is fitted with radar, turn it on as soon as the visibility is reduced, and...

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Strategy and limitations 1

If you are in a busy shipping lane, mark you exact position, if possible, on the chart, note the positions and courses of other vessels. Alter your course immediately to get clear of the lane and other ships as soon as you can, sailing to more...

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Strategy and limitations 2

When you are navigating near the coast or in a channel and the visibility is restricted, consult the echo sounder or depth recorder, Try to follow a depth contour on the chart that provides navigable waters and is clear of charted hazards...

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Sound signals 1

Here are the sound signal rules to be followed by vessels in restricted visibility: A power-driven vessel underway must sound one prolonged blast every two minutes. A power-driven vessel underway but stopped and making no way through the water...

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Sound signals 2

A vessel at anchor may in addition to the bell and/or gong, sound one short, one prolonged and one short blast to give warning of her position, and of the possibility of collision, to an approaching vessel. A vessel aground must ring the bell...

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Introduction

Navigation lights are used to prevent collisions at night or in times of reduced visibility. Vessels are required to show the proper navigation lights from sunset to sunrise in all weather conditions and in conditions of reduced visibility. All...

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