Please select your home edition
Edition
Seaview Studio 2020 LEADERBOARD

Global Solo Challenge: Radar on sailboats - making the most of it and using it safely

by Global Solo Challenge 28 Aug 13:23 BST
Radar display - 4 miles range © Global Solo Challenge

What is a Radar

The word radar is an acronym coined by the US Navy at the beginning of World War II with the meaning of "Radio Detection And Ranging". Its application for military purposes has spread over time, also finding diffusion in the civil field in aviation and in the nautical sector.

This tool provides two pieces of information, the distance and the angle relative to our position of any solid object or surface in the range of our antenna. The principle of operation is not conceptually different from the mechanism that allows bats to fly and hunt in the dark. The bat emits ultrasounds and perceives its own sound waves reflected from its surroundings. He is thus able to mentally reconstruct the map of the cave in which he is flying and the location of the insects he is hunting.

The device, instead of emitting ultrasounds, emits radio waves through a rotating antenna. In addition to emitting, it receives the reflected waves of surrounding objects. Knowing the angle relative to the boat of the rotating antenna at the moment of transmission, you can know the distance and angle. This is by calculating the time it takes for the reflection to return. A computer then transforms this information into an image visible and understandable to the human eye which is presented on the display.

What's it for?

It is a precious navigation aid, especially in situations of reduced visibility. It can be used to know the position and distance of other boats, other obstructions such as rocks and buoys and the coast. For example, in fog, radar can be used to avoid collisions. Not only that, also to find the mouth of a port or the shape of a breakwater. Sound alarms can be activated on each device to warn us of the presence of ships or obstacles approaching relative to our position.

It is very effective for monitoring the movement of another ship and safely assessing whether we are at risk of collision. With the naked eye, even in broad daylight and with good visibility, it can be difficult to assess the true distance of a fishing boat. Being able to understand in which direction it is moving and if you need to manoeuvre to avoid it. Radar can make these situations less stressful. At night and in case of fog it can become an essential tool to ensure safe navigation.

Equipment for civil use

The instrument for civil use, simplifying to the extreme, is composed of a transmitter, a rotating antenna, a receiver, a processor and a display. The rotating antenna is often only one and is used both for the transmission of impulses and for the reception of reflections. All devices have a rotating antenna. In the dome radars typical of small fishing boats and other boats, the rotating antenna is hidden under the plastic cover of the dome.

Every wave transmitted by the radar that is reflected by a distant object returns very weak, some surfaces and materials reflect better than others. The metal surfaces of a ferry reflect well, but the fiberglass of a boat does not reflect at all.

In addition to the properties of the various materials, it is necessary to simply consider the power of our instrument, a crucial factor that determines its range. Power also means electricity consumption and inevitably the instruments installed on sailboats are not very powerful. They have a typical rated range of up to 16 miles but perform best in the 3 to 6 mile range. It may not seem like much but it is perfectly adequate in order to assist in navigation in conditions of reduced visibility.

Continue reading the full article here...

Related Articles

Global Solo Challenge: Battery & power management
Almost every sailing or motor yacht has on board a more or less complex electrical system Almost every sailing or motor boat has on board a more or less complex electrical system and a variable number of batteries. This depends on the size of the boat, the instruments installed and the equipment on board. Posted on 29 Sep
Global Solo Challenge: Facing Cape Horn in a storm
A story of rounding the famous landmark After the second storm, the wind dropped rapidly, and within half a day it went aft and we could even hoist the big gennaker. Hugo and I celebrate, laugh, joke. Posted on 27 Sep
Global Solo Challenge: Pasquale, gentleman sailor
Pasquale De Gregorio embodies a dream, that of racing the most extreme solo race Pasquale De Gregorio is one of the closest sailors to all lovers of the sea and sailing. Pasquale is an example, he had to conquer the sea, he was not born near it, it was love at first sight, which lasted a lifetime. Posted on 25 Sep
Sail changes on an offshore racing boat
Sail crossover is a term used to refer to a boat's combination of sails for all conditions Sail crossover is a term used to refer to a boat's combination of sails for all conditions. Each sail has a range of use, beyond which a smaller sail will replace it. Posted on 18 Sep
Jean-Luc Van Den Heede interview
An in-depth analysis of solo sailing and of the problems to be faced such as food and sleep A long interview with Jean-Luc Van Den Heede, the last seadog, the man of records and the "long route" who talks to us about the mother of all non-stop solo circumnavigations. Posted on 13 Sep
32nd entry for the Global Solo Challenge
The momentum of the event continues to grow The momentum of the Global Solo Challenge (GSC) continues to grow. Organisers are delighted to announce that the 32nd entry is also the 3rd Australian skipper, with a 50+ foot performance boat, who at this stage wishes to remain anonymous. Posted on 6 Sep
How to optimise route based on weather predictions
Optimising the route: understanding the problem to be solved. One recurring question among the novice offshore sailor is how to optimise your route when sailing. The practice is known among sailors with the French name of Routage or the English name of Weather routing. Posted on 23 Aug
Solving problems with inboard diesel engines
Some of the more common issues seen with sailboat engines To fully understand the operation of the inboard engine of a sailboat, you need to study at least the basic principles. Refer to the many resources available online, a short google search will bring up many results. Posted on 21 Aug
How to make the most of wind maps and grib files
Understanding the limitations, from the Global Solo Challenge Wind maps derived from grib files are nothing more than one of the possible representations of the development of the meteorological situation. Posted on 18 Aug
Global Solo Challenge welcomes 28th entry
William Croxford from Kettering enters the race William Croxford from Kettering, England, has dreamed of sailing around the world since childhood, watching and reading about Ellen MacArthur and Sir Robin Knox-Johnston made him always dream of completing a circumnavigation. Posted on 9 Aug