Please select your home edition
Edition
Barz Optics - Kids range

AIS - a major navigation advance

by Powerboat-World.com on 5 May 2007
ComarSLR200 (1) Oceantalk www.oceantalk.com.au
‘Greatest thing since sliced bread!’ That was the pronouncement of Sydney sailor Ian Potter of Sundancer II. He was talking about an AIS (Automatic Identification System) Receiver. Sundancer has had a chance to try out this brand new technology on their way across the Indian Ocean and up into the Med. over the last year.

With the danger of collision with a any fast moving ship always on the mind of cruising sailors and crusing motor yacht owners, this is a brilliant innovation that enables you, not only to see where the ships are, but to identify them as well. With a possible 12 minutes between horizon and collision, on any ocean, anywhere, it is not a small issue.

Ian had more to say: 'We were picking up ships at over 20 miles away and its so much easier to call them by name instead of 'vessel in approx position etc' . Going past the bottom on India we had up to 15 vessels displayed at one time.’

As Robin Kydd from Oceantalk the Australian distributor for the well proven Comar AIS system explains 'This technology is certain to give recreational boat owners an added dimension of safety and peace of mind through commercial shipping technology.


AIS transponders are now carried by all vessels over 300 tons. The AIS transponders transmits relevant vessel information: including Position, Speed, Heading, Call sign (MMSI number) Ships Name and Destination via a simple VHF signal.

This information can now be received by the AIS receiver on your own boat for display on the chart plotter screen. ( a system similar to aviation transponders that allow air traffic to be monitored and tracked on an air traffic controller’s screen.)

The AIS data is incredibly useful to any skipper. You can view an unknown vessel’s MMSI number and call sign: (to allow digital selective calls (DSC) to be made to that vessel.) Knowing the intended course and speed of an oncoming ship could assist you in plotting an alternate course. Keeping an eye on precisely how many ships are in the area, whether they are leaving port or entering. Even to record the Ships position and name in your log could be useful.

The most important advance in navigation, probably in the last five year. It adds to radar, chart plot, allow skippers to concentrate on the smaller boats that do not have AIS

Comar produce two main models, SLR200 Receiver only, and the CSB200 Transponder (Transmits as well as receives.) The units only require a marine style VHF Antenna. Recreational vessels are not legally enforced to carry either type but would be encouraged to fit the SLR200 Receiver in the very least.

The Comar SLR 200 AIS Receiver decodes and allows display of any AIS data received on Raymarine C and E Series displays. The SLR200 unit retails for less than AUS $1000 and is a worthwhile addition to any navigation system.

The Comar CSB 200 transponder is both a receiver and transmitter of AIS data. It gives recreational boats the ability to transmit their own AIS signal in order to recognize and be recognized by other AIS equipped vessels.

Introduced primarily as a vessel safety measure, all vessels over 300 tonnes will be required to fit an AIS transponder by the end of 2007. The safety benefits of AIS data means that many more, non-legislative vessels, are fitting both AIS receivers.

The introduction of affordable AIS receivers, such as the SLR-200 from Comar, enables users to see at a glance a visual display and detailed data about vessels in the area. This is especially useful at night, in fog, or in busy shipping lanes. The speed and accuracy of AIS information is paramount, with information updated every three seconds to six minutes, depending on the category of information, the speed and the rate of turn of the vessel.

The SLR-200 will receive and display the name of the vessel, call sign, type of vessel, destination, speed, course, heading, rate of turn, position, navigation status, vessel dimensions and MMSI number. With all this data, the user can ascertain and monitor vessel movements in the area, plot the progress, changes in heading and speed of nearby vessels, and, if required, call up the vessel.

Designed for use in the hostile marine environment, the SLR-200 is a robust, dual channel AIS receiver, incorporating a synthesised VHF receiver unit in its compact casing. Measuring just 140mm by 120mm by 50mm, it comes complete with trunnion mount, power cable, PC serial cable, NMEA cable and a combined installation/instruction manual.

The SLR-200 is quick and easy to install, requiring a 12/24vDC power source. It is connected to the PC via the serial port and to an external VHF aerial. For ports and harbour authorities, the SLR-200 is an affordable alternative to a high cost full Class ‘A’ unit, enabling them to monitor traffic within the VHF range, track vessels in the areas, and check on the legality of transit, and compliance with speed regulations

The data available from the SLR-200 provides an immediate, visual insight into the status and movements of other vessels in VHF range. AIS capability is now included as a standard feature on the majority of PC navigation software. Integrating AIS data onto the vessel’s electronic chart display instantly improves the safety levels on board, with the quick access to a MMSI (Marine Mobile Service Identity) can often help avoid a potential collision.

Class A AIS unit broadcasts the following information every two to 10 seconds while underway, and every three minutes while at anchor at a power level of 12.5 watts:

  • MMSI number - unique referenceable identification
  • Navigation status - not only are "at anchor" and "under way using engine" currently defined, but "not under command" is also currently defined. 
  • Rate of turn - right or left, 0 to 720 degrees per minute
  • Speed over ground - 1/10 knot resolution from 0 to 102 knots.
  • Position accuracy - differential GPS or other and an indication if RAIM processing is being used
  • Longitude - to 1/10000 minute and Latitude - to 1/10000 minute
  • Course over ground - relative to true north to 1/10th degree
  • True Heading - 0 to 359 degrees derived from gyro input
  • Time stamp - The universal time to nearest second that this information was generated

 

In addition, the Class A AIS unit broadcasts the following information every six minutes:

  • MMSI number - same unique identification used above, links the data above to described vessel
  • IMO number - unique referenceable identification (related to ship's construction)
  • Radio call sign - international call sign assigned to vessel, often used on voice radio
  • Name - Name of ship, 20 characters are provided
  • Type of ship/cargo - there is a table of possibilities that are available
  • Dimensions of ship - to nearest meter
  • Location on ship where reference point for position reports is located
  • Type of position fixing device - various options from differential GPS to undefined
  • Draught of ship - 1/10 meter to 25.5 meters [note "air-draught" is not provided]
  • Destination - 20 characters are provided
  • Estimated time of Arrival at destination - month, day, hour, and minute in UTC


Robin Kydd Managing Director of Ocean Talk: 'I recently brought a boat down from Phuket to Singapore, fitting with the Comar SLR200. With heavy shipping traffic, it really simplified the navigators task. Knowing what the commercial traffic was doing, with speed and bearing, we could easily see what boats were of no concern and that let us worry about other smaller ships. This is certainly a major advance for leisure boater.

As the region’s leading supplier of marine electronics for many years, we are thrilled to be able to off the proven Comar Systems. This is cutting edge technology, a world first, and a product ideally suited to the Australasian boating market. And as with all our products, we have the expertise, technical support and after sales service to do the system justice,' .

Find out more by calling Oceantalk on 02 9981 9500, fax 02 9981 9555, email sales@oceantalk.com or visit www.oceantalk.com

www.sail-world.com/send_message.cfm!Click_Here!same to comment on this article
Southern Spars - 100Zhik Yachting 660x82upffront 660x82

Related Articles

2014 J/24 World Championship - Will Welles’ Cougar clinches
Welles had used his throw-out on Thursday, so the only way to assure a win was to stay ahead. 2014 J/24 World Championship - With just a few points between Will Welles Cougar (USA) and Mauricio Santa Cruz Bruschetta (BRA) there was no room for error in the final two races of the 2014 J/24 World Championship hosted by Sail Newport.
Posted on 27 Sep 2014
J/24 World Championship - Will Welles hangs on going into last day
The Race Committee chose to sail inside north of the Newport Bridge for races seven and eight of the 2014 J/24 Worlds. With marginal conditions and diminishing visibility on the ocean course, the Race Committee chose to sail inside north of the Newport Bridge for races seven and eight of the 2014 J/24 World Championship hosted by Sail Newport. Will Welles’ Cougar (USA) sailed his throw-out in race seven but came back with a solid six in race eight to hold onto the lead with a total score of 31 points.
Posted on 26 Sep 2014
2014 J/24 World Championship - Will Welles holds advantage
After a struggle to set the line square to the shifting wind, the fleet got off two more races at 2014 J/24 World Champ 2014 J/24 World Championship - After a struggle to set the line square to the shifting wind, the fleet got off two more races at the 2014 J/24 World Championship hosted by Sail Newport. Will Welles’ Cougar (USA) held the lead with a four, four respectively for a total score of 16 points.
Posted on 25 Sep 2014
2014 J/24 World Championship - Will Welles takes lead
Teams battled today in more stable sea conditions on ocean course in wind speeds from 10 to 14 knots out of southwest. 2014 J/24 World Championship - After a morning postponement ashore, the fleet got off two more races at the 2014 J/24 World Championship hosted by Sail Newport. Will Welles’ Cougar (USA) moved to the lead with a nine, one respectively.
Posted on 24 Sep 2014
J/24 Worlds - Opening day leaves two teams tied on points for lead
Newport, Rhode Island welcomed 70 teams from around the globe with wind and waves on the first of five days 2014 J/24 World Championship - Newport, Rhode Island welcomed 70 teams from around the globe with wind and waves on the first of five days at the 2014 J/24 World Championship. The top of the fleet saw some familiar names but also some fresher faces. Mark Hillman’s Sokokumaru (USA) and Vernon Robert’s Gringa DC (Chile) are tied at five points, with Hillman having the first-place advantage thanks to
Posted on 23 Sep 2014
J/24 World Championship - 35th anniversary preview
Back in 1979, no one would ever imagine the J/24 class would achieve such enthusiastic support and popularity. Back in 1979, no one would ever imagine the J/24 class would achieve such enthusiastic support and popularity that in its first World Championships in Newport, RI, hosted by Ida Lewis YC and sponsored by Bacardi Rum, that 69 boats would participate in that event.
Posted on 20 Sep 2014
J/24 World Championship - Excitement builds for Newport racing
Seventy-one teams from 13 nations are registered to compete in the 2014 J/24 World Championship. The legend lives on 37 years after Rod Johnstone built the first J/24. Seventy-one teams from 13 nations are registered to compete in the 2014 J/24 World Championship in Newport, Rhode Island.
Posted on 19 Sep 2014
World's tiniest PLB now certified for use
Ocean Signal's rescueME PLB1, the tiniest PLB in the world, has now been certified for use in Europe and the USA The tiniest PLB in the world, introduced to the sailing world in January, has now been fully certified for use throughout Europe and the USA after being awarded relevant COSPAS-SARSAT and product approvals. The product will be available in Australia after being launched later this month.
Posted on 5 Apr 2013
Low DSC connect rate-Sailor irresponsibility or technological failure?
Is the low take-up of available DSC connection to radio because of sailor irresponsibility, or is it more complex? Recently we published a story about how few yachts had their Digital Selective Calling (DSC) equipped VHF radio connected to their GPS so that their position would be recorded in an emergency. The tone of the article suggested that the low take-up was an indication of the irresponsibility of sailors, but responses to Sail-World after the article suggest that the situation is more complex than this
Posted on 27 Mar 2011
Sailor's aid or sailor's nightmare - the tides explained
It's not surprising if you don't exactly understand tides - it took a lot of figuring out over the ages As sailors, we all know that tides come twice a day, vary according to the moon, and, depending on where you are sailing are either unimportant, reasonably important, or critically important to a successful completion of your voyage. But why the moon? and if the moon only circles the earth once a day, why are there two tides? Here, Grant Headifen of Nauticed, explains
Posted on 18 Sep 2010