AIS - Automatic Indentification System

There are 3 inimitable components in operating an electronic navigational aid.

• Competent and skilled Operator (user)
• Precise/High Quality Hardware
• High Quality/ User friendly Software

The hardware component is responsible for extracting data and feeding this into the software component.

One of the most common questions we get asked is:

"Can you use AIS as the source of data for displaying own-ship information?"

Most opt for AIS as a low cost source of own ship data, however as the old saying goes - Rubbish IN, Rubbish OUT

So to answer the question - NO, largely because of poor quality source data that you get from the fitted AIS system (including gyro errors, lack of ROT data, and imprecise GPS positions).

Inadequate physical installation of the systems aboard many ships also contributes to the problem. Problems with the “mandatory” pilot plug include vessels which are not fitted, difficulty in locating it, and inability to get a data stream due to incorrect wiring. All too often, even when a connection is successful, the high quality data required for close-in pilotage work is simply not available. Distractions while finding and making the connection, combined with unreliable data, do not contribute greatly to vessel safety in pilotage waters.

The result is that in its current state of development, although AIS is very useful for providing information on other ships in the vicinity - particularly if it is displayed on the radar or ENC – the pilot is unlikely to be able to rely on the navigation data provided from the AIS plug for safe, accurate own-ship pilotage. The Nautical Institute has a forum on AIS which provides some interesting insights into these sorts of problems – see http://www.nautinst.org/ais.

You can also click on the images below to view some of the real differences between data input from AIS and data input from HarbourPilot. Each recording shows the same vessel at the same time. The first part of the recording shows the display using AIS as the input source, and the second part shows with HarbourPilot as the input source. Each recording has a narrative.

	AIS vs HarbourPilot Input in Navigational Mode.
	AIS vs HarbourPilot data Input in Docking Mode

When considering this type of investment it is mandatory to do the research and understand what it is that you are actually purchasing.

Read our articles for more information:

• Electronic Navigational Aids for Pilotage
• The new generation of Portable Pilot Aids
• Portable Aids for Pilotage

Feel free to contact us with any question you may have in regards to Portable Electronic Systems for Pilotage. We will be more than happy to help.

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