What are AIS Tracking Websites and how do they work?
If you are travelling and want the folks back home to see where you are, or even if you just want to get an idea of what vessel traffic is like , prior to leaving home; AIS Tracking Websites have become a very popular and useful hobbyists tool.
Sites such as marinetraffic.com and vesseltracker.com offer a free service where web users can search for vessels that are represented on maps or even old satellite images.
Why can't I see my vessel on the AIS website?
On occasions, we are asked to explain why a customer’s vessel might not be appearing on these sites as there may be some concern that the unit is not operating correctly.
If you are concerned that this may be the case with your AIS transceiver then please consider the following:
Coverage: Not all AIS websites offer complete coverage, so there is a chance that you may be out of range of a receiving station for that site.
Antenna setup: If you are being seen by other vessels around you, but not by the AIS website, then the issue could be associated with your choice/installation of VHF antenna. If in doubt, refer to the user manual for advice or contact us for help.
Unit configuration: Make sure that your AIS transceiver is correctly setup with its complete vessel details and that it is connected to a GPS antenna (as per the user instructions).
How do I install my Em-Trak AIS?
EM-TRAK transceivers are specifically designed for installation simplicity. Every em-trak transceiver is supplied with clear and straight forward instructions and help is always on hand, get in touch.
Here is an example of the connection layout when installing our B900-series AIS.
All units are supplied with a mounting bracket, template, mounting hardware, power/data cable and VHF connection cable with PL-259 connectors.
Note: The USB cable,
NMEA 2000 drop cable and
VHF Antenna is not included.
external GPS anternna is optional, but may be required when fitting below deck on Steel Vessels.
Can I connect to my AIS with my Tablet or Smartphone?
Only certain models of em-trak AIS transceivers will connect to your device and any navigation application you are using – please note that you must have a navigation application running on your tablet. This will enable you to see AIS targets on your screen.
WiFi & Bluetooth enabled variants (
B952/B954) can be connected wirelessly to any mobile device. To establish a connection with a mobile device you will need to select your transceiver from its list of detected devices using the device name or SSID - at default it appears as _ but it can be changed using the WiFi tab on proAIS2 software if required.
To stream AIS data to a navigation application you may then need to enter the IP address and port number. This is also displayed in the WiFi tab of proAIS2 and can be changed if required.
If you aren’t sure just
What is NMEA2000?
NMEA 2000 is a ‘plug and play’ open standard designed by the NMEA to help them achieve their mission by standardising the messages and connector system used for devices in the marine industry. The network carries data sentences for commands as well as messaging (tank levels) between NMEA 2000 devices.
There is a common misconception that the term ‘open standard’ means freely available when in fact it means that the standard is available to buy at a reasonable cost from their website. It is important to remember that the NMEA is not for profit (NFP) and the standards create an important source of income so that they can continue to exist.
What is the difference between NMEA 2000 and NMEA 0183?
NMEA 2000 simplifies the connection – The NMEA 2000 backbone is a single trunk cable to which the appropriate T-pieces, network cables and terminators can simply screw onto. Unlike connecting NMEA 0183 open cable ends.
Using NMEA 2000 gateways, like the
NGW-1, allows compatibility between the two networks.
How to Install NMEA 2000?
NMEA 2000 networks should be installed as per the NMEA 0400 specification with guidance on power insertion and supply connectivity, length of cables, wiring of field connectors etc…
The main communication channel of the NMEA 2000 network is the backbone to which your NMEA 2000 devices connect. Each NMEA 2000 device connects to the backbone with a T-connector. The NMEA 2000 backbone must be connected to 12 V DC power, and terminators must be installed at both ends of the network to function correctly. Daisy chaining is not allowed.
Please also note that all wiring should be done following your local wiring regs.
How many devices can be on an NMEA 2000 network?
An NMEA 2000 network can have up to 50 physical devices connected to the network at any one time. Part of the NMEA 2000 standard also details that when connecting or disconnecting a device, it shall not interfere with any other devices or cause any conflict on the network.
What is a PGN?
All data transmitted on an NMEA 2000 network are organised into groups. These groups are identified by a parameter group number (PGN) that describes the type of data contained in the group.
Why not try our
NMEA 2000 PGN search to find definitions by Number, Name or Category.
What is the maximum length for a drop cable?
The maximum length of a single drop cable to a NMEA 2000 device is 6 m (20 ft).
What are the power requirements on the NMEA 2000 network?
Your NMEA 2000 network must be connected to a 12 V DC power supply. Do not connect the network to any other voltage source, such as a 24 V DC power supply. Supply power as close to the middle of the backbone run as possible.
Do not connect the NMEA 2000 network to power in more than one location unless a Network Bridge Interface is used (standard practise for larger systems where voltage drops are expected).
What is a Load Equivalance Number (LEN)?
A Load Equivalence Number or LEN is a whole number used to express the amount of current that is drawn from an NMEA 2000 network.
Each device should have an LEN specified on the product or in the product documentation.
One LEN is equal to 50mA. If a device draws 151mA of current from the network, then its LEN is 4. Note that the LEN is always roundedup to the next whole number.
The LEN number is used to calculate the voltage drop in the NMEA 2000 network when multiple devices are connected.
The formula for calculating the voltage drop is:
Voltage Drop = Cable resistance (ohms/m) × Distance (from the battery to the farthest device, in meters) × Network Load × 0.1
Is my product NMEA 2000 Certified?
Only NMEA 2000® certified products have met all requirements and have full NMEA 2000® certification.
Products that are marketed or labelled: "NMEA 2000 compliant" or "works with NMEA 2000" are not NMEA 2000® certified and may not interoperate properly with other NMEA 2000® certified products.
Check that your product is NMEA 2000 certified by searching the
A-Z List of Certified Products.
Can my old equipment be repaired?
We like taking a practical approach when it comes to assessing damages. Depending on a few factors such as age of the equipement and extent of any damages, we might suggest that the unit gets tested in our workshop.
The key factor to consider is wether it is worth carrying out any type of repair at all. When the equipment is 10 years or older it may not always be economical to make repairs, as replacing one component doesn't guarrantee the reliabilty of the rest, and it could lead to another failure and more costs.
How do I return a product?
All goods being returned require an RMA number.
We normally aim to process your request within 1 business day and will contact you with any details of how to proceed.
Our RMA Number
must be referenced and clearly marked on all documentation and goods being returned.
More information in our
Returns Policy and
Sign up or Log in to
Complete our RMA Request Form
What is the Colour Code Wiring for NMEA 0183?
There is a multitude of colour codes used between brands, so always consult with the installation manual for your product.
If you have purchased one of our Actisense Products the NMEA 0183 colour code is as follows:
Talker A/+ = WHITE
Talker B/- = BROWN
Listener A/+ = YELLOW
Listener B/- = GREEN
NGW-1 was first created in 2008, subsequent changes to the Standard do not require existing products to be changed.
Care is needed – it is possible to damage or overload the output of a newer differential device if it is incorrectly connected to an older device. This is because the older devices
used ground as the return, whereas the newer devices actually drive the NMEA “-/B” line between 5v and 0v. Thus, connecting this output to ground will result in high currents
being drawn by the driver instrument, resulting in potential overheating and damage to the driver circuits.
Who is the NMEA?
The NMEA, which stands for National Marine Electronics Association, is committed to enhancing the technology and safety of marine electronics through installer training and interface standards.
NMEA members promote professionalism within the marine electronics industry.
Read more at
VHF & Antennas
Marine VHF Radio Licence: How to go about getting qualified?
All marine VHF users should be suitably qualified/licenced and have passed the RYA Marine Radio Short Range Certificate (SRC) course which is run at many sailing clubs, water sports centres and colleges in the UK.
The SRC is the minimum qualification required to operate marine VHF radio equipment on a UK flagged vessel. This includes both fixed and handheld equipment with and without Digital Selective Calling (DSC).
SRC course may be taken in a classroom or online through an RYA Recognised Training Centre. The exam is a combination of a written theory test and practical assessment in the use of Marine VHF DSC radios. Candidates must be 16 years or older on the day of the exam.
Do I Need A Marine VHF Licence?
Anyone who uses a Marine VHF Radio needs a licence. If you are a sailor, powerboater, kayaker, angler or even a paddleboarder, you will most certainly need a marine radio. It is one of the most important safety tools you can take to the sea and will help to keep you safe allowing you to contact other boat users, marinas and the Coastguard.
If you need a radio, you may need both a radio licence and an operator's licence. This depends on the type of radio you have and how you use it.
Once installed in a vessel, a marine VHF radio requires a ship's radio licence. This can be obtained via the
If you sell the boat or radio you can now transfer the new owner's details over to the MMSI (Maritime Mobile Service Identity) number in the radio (other way round – transfer the MMSI number). A few years ago you had to return the radio to the manufacturer to get the MMSI number removed and the new owner would have to apply for a new one to program into the set.
Once an MMSI is registered with DTTS, the ITU and the MCA are informed so if searched on the ITU (International Telecommunications Union) MARS database (Maritime Access & retrieval system) your MMSI number will appear. You would need to input the ship’s name and country and search for the owner’s details. The ITU and MCA are informed to assist with SAR (Search and Rescue Operations).
What is an MMSI number?
MMSI (Maritime Mobile Service Identity) numbers are a series of nine digits, which are used to uniquely identify a radio station or group of radio stations.
When sending a DSC message the MMSI is automatically included, and you can address messages to specific vessels or groups using their MMSIs.
The MMSI has a standard format (just like a telephone number) and it identifies the type of station, country of registration and vessel identity.