Frequently Asked Questions

What is AIS?

AIS is short for Automatic Identification System, which is a globally developed protocol to enlarge safety. AIS sends and/or receives data through FM frequencies (same as the VHF). This is standardised information and is equal for all AIS (with special additions for class A AIS). It contains information about the ship: call sign, dimensions, course, speed, type, etc. Although it’s not intended to have 100% coverage, it offers important information about surrounding vessels.

There are three categories in AIS:

• Class A AIS:
  This type of AIS is used for all commercial vessels.
• Class B AIS:
  This is AIS for leisure. The class B AIS has the same functionalities as the class A, but it has been simplified for yachts. For instance the data frequency has a larger interval.
• AIS receivers:
  AIS receivers receive information from surrounding vessels (both class A as class B), but don’t send information to others.

Which information does AIS transmit?

• Statistic data, such as call sign, MMSI number, dimensions, type of ship (e.g. cargo, ferry, sailing)
• Dynamic data (based on GPS), such as position, heading, speed, bearing, range, rate of turn
• Travel data (only commercial vessels), such as destination, number of passengers, description of cargo

What is an MMSI number?

MMSI is short for Maritime Mobile Service Identity. This number will be officially allocated to your ship by the local authorities. The B transponder transmits this number, so you must apply for it before you can use your AIS.

Be aware that the MMSI number belongs to the ship, not to a person. So if the AIS is being reinstalled on another ship, another MMSI number must be programmed.

Because receivers don’t send information they don’t need an MMSI number.

What has VHF got to do with AIS?

The AIS uses VHF channels to transmit data. There are two channels available for AIS: when the first channel reaches its limit, the second channel will be enabled. A dual banded AIS transmits data through both channels, so you’re sure that there is no information missing.

When can I use AIS?

The AIS receiver can be used always and everywhere. Because it just receives information and it doesn’t send any data there are no restrictions.

The AIS transponder (class B AIS) is designed to use on ships. It is required to have an MMSI number programmed into the AIS. Because it sends data, it’s compulsory to have a VHF certificate and have the VHF radio switched on, so that others can contact you.

The pros and cons

Pro’s

• Increases safety
• There’s many information about surrounding ships available, which makes it easier to make clear and safe decisions
• The range is about 10 nMile (or more, depending on the VHF antenna)
• There’s no blockage of the signal by buildings, dikes, floodgates, like radar has
• The available information provides possibilities to anticipate in many ways, such as controlling bridges and floodgates.

Con’s

• Not every ship has AIS, so can’t see them all. Although commercial vessels are almost everywhere obliged to have AIS installed.
• All data is public, perhaps there are moments you just don’t want to be seen. Watcheye offers the silent modus for these moments: you’ll still be able to see others, but they can’t see you.
• Some people find it a bit complicated to install the AIS and connect it to their equipment. Please do not hesitate to contact us if you have questions about your installation.

Is Watcheye compatible with my other equipment?

AIS is an globally developed system. Which means that the data is standardised. It depends on the device to which the AIS is connected: is it AIS compatible? All manufacturers specifically mention if their product supports AIS.

There is a difference in which data protocol is used in the AIS. There are two universal protocols: NMEA0183 and NMEA2000. Watcheye is proud to mention that our products support both protocols.

What is a timeslot?

The background of the encryption of the data is based on TDMA, which is short for Time Division Multiple Access:

• Class A: (commercial vessels), is based on SOTDMA (self organised TDMA) on 12W. It has a default transmit range of 2-3 seconds. If the status of the ship changes in moored or anchored, the interval increases.
• Class B: (leisure vessels), is based on CSTDMA (carrier sense TDMA) on 2W. The default transmit range is every 30 seconds. If the speed is less than 2 knots the interval will increase up to 3 minutes.

These intervals are described for the dynamic information.

A static report is transmitted only every six minutes (for both class A and B).

Mounting the AIS in limited space

The equipment is designed to be mounted both vertically and horizontally. It is not necessary to have the AIS in sight, as long as the cables are connected to your chart system.

Make sure that the internal GPS has a signal: we would advise you to mount the AIS just below deck. First test if the GPS is functioning, before you mount the AIS in definite.

If you use both AIS and splitter you might consider to mount them on top of each other to save space.

To what can I connect the AIS?

The Watcheye AIS R receiver and B transponder are programmed for both NMEA0183 and NMEA2000, which makes is possible to connect it to all equipment, based on one of those protocols and compatible with AIS.

There are brands which use their own data system, but usually they also provide the connection to transform the NMEA data to their protocol.

Plotter

Older plotters are not always compatible with AIS, but often the manufacturer provides updated software for this use.

Laptop

There’s many chart software available for computers, make sure that it’s compatible with AIS. We think opencpn (htttp://opencpn.org) is a suitable program, especially while it’s open source.

Tablet

There are many apps available in iTunes and Playstore. Please check if the app uses your AIS data, instead of the data from the internet.

To make a wireless connection from the AIS to your tablet we’ve developed the Watcheye Wave. This device transforms the AIS data in a wifi signal.

Splitter or extra antenna?

The Watcheye S splitter has been tested thoroughly and the discrepancy between a separate antenna is negligible. The splitter offers the possibility to use the VHF antenna for both VHF and AIS, so it’s much easier to install.

For longer journeys or longer distances we would advise to install a separate antenna, this offers two completely separate systems and therefore more safety.

I want a separate antenna, what do I need to know?

Antennas transmit in a horizontal range. Therefor it is important that the second antenna is mounted on a different level than the first one.

I’ve connected my Watcheye B AIS transponder, but I’m not visible on the websites (such as marinetraffic.com)

Please note that these sites aren’t very reliable and often filters are used in what’s shown online and what’s not. Our experience learns that a ship is displayed whenever it starts to move.

The best way to check if your AIS is active is to start the ProAIS2 software or to ask another skipper.

On what operation system I can install the software?

Windows XP, vista, 7, 8, 10 and MAC

I want to reset the MMSI number of my Watcheye AIS transponder

Ask your local supplier.

If necessary, send the AIS to us so that we’ll do it for you for € 24,95 excl shipping.

The device is not working (well), what should I do?

• Read chapter 6 in the manual
• Connect the device to ProAIS2 and check the diagnostics tab for errors
• Ask your supplier for help
• Contact our support office, preferably by email at support@watcheye.nl and send us additional information such as screenshots and a log file

There’s a problem with the antenna

Check the VSWR in the ProAIS2 software, this should be any value between 1:1 and 3:1. All other values might imply an error in the antenna. This can be caused by e.g. a dysfunctional antenna, a bad cable, bad connectors, interference of other antenna’s or equipment, etc.

I want to send the device back for repair

All our products have 2 years of warranty. Have you checked all the above, but the problem persists, please send the device back to our support time for repair. If the malfunction isn’t covered by warranty we will inform you about the costs for the repair. If your device is older than 2 years we will charge € 150,- to make a diagnosis.

Please send us an email to inform us about the problem, including:

• Date of purchase (with a copy of the invoice)
• The serial number
• Date of installation
• Description of your configuration/installation (using laptop/plotter/splitter, etc)
• Description of the defect

In general it takes four to six weeks to repair and return a device.