When I talk to people about what we do in Atlantic Source with different tracking technologies, they normally say “ah, ok, so it is like a GPS”. I normally make a point saying, “well, yes, GPS let’s you know where you are, but it does not send your information anywhere, since this info stays with you. We do provide the means to send that information elsewhere, then you decide to keep it either privately or share it with others”.
So, what solutions are there available to track ships, yachts, and other marine assets?
Some of the key issues to consider:
- Frequency of messages
- Price (acquisition and operation)
- Ability to receive others’ positions
Most of these items will be related to the technology use use to send out our GPS position. We are going to focus in three:
- Cellular phone network (GSM/GPRS/EDGE/3G/…)
- Satellite communications (Inmarsat, Globalstar, Iridium,…)
- VHF radio using AIS (Automatic Identification System) standard
Cellular phone network
This is probably the cheapest for acquisition, since any smartphone will do the work, and can also be very cheap for operation because you can make use of your regular data plan. Position messages are small messages so you should be able to fit a lot of them in your monthly data bundle.
The major drawback of this solution is coverage. If you are planning to leave the coast out of sight, or even, just go off more than 10 miles, you may start losing coverage so your device will not send any additional data.
Besides, if you change country in your trip, you will have to face roaming charges to your data, and this is likely to be outrageously expensive.
So, altogether, the cellular phone network can be a good solution for inland waters or sailing within a bay or close to the coast, but not if you are planning a long journey.
Aimed at providing global coverage, satellite communications are the best option if you are navigating in open seas.
Besides, when compared to mobile network communications, satellite offers a nice advantage: it has no roaming charges. On the other hand, data transmission is more expensive, so with satellite you should reduce the amount of position messages that you send to what is really needed. Maybe a message every 3/4 hours?
VHF radio using AIS
AIS, Automatic Identification System, was designed to improve safety-at-sea. It is a bidirectional tracking solution, meaning that you can transmit your position and see the position of other boats. This is a major difference with the other two options that we discussed above. We can say that this system is valuable as long as most of the vessels use it, and it is based on publicly sharing the position.
So why have we put it here? because if you are doing coastal navigation, you will find that there are plenty of base stations, many of them amateur, that cover the coast and share the received information thanks to great software like ShipPlotter or AIS Dispatcher. You can see examples of AIS maritime traffic here.
AIS transponders and receivers use the VHF designated AIS frequencies, so transmission and reception are both free. On the other hand, the information you transmit is available to anyone with a receiver, there is no possibility to encrypt it (unless you are in the military).