MOB integration and intelligent alarms
If someone with a lifejacket equipped with a personal AIS transmitter falls overboard the Cortex system will automatically switch to a dedicated MOB screen as soon as the personal AIS unit is activated. At the same time an allstations DSC message for MOB (rather than a general DSC distress message) is sent, which helps to free up time to start the rescue procedure on board.
If the transmitter IDS are preprogrammed into the Cortex system with crew names it will know exactly who’s in the water, which can be beneficial on a boat with a large crew. If a personal AIS does not automatically trigger the MOB mode, a press of the MOB key will drop a flag in that position, which gives a location to return to, or from which to start a search pattern.
And instead of the near-ubiquitous beeping alarms, the Cortex system provides an informative audible message, such as ‘Collision alert!’ and ‘Man Overboard!’ These escalate in volume until acknowledged.
Remote monitoring
This was built into the system from the outset, with a smartphone app as the interface when away from the boat.
For example, if you’re ashore with the anchor watch function set you’ll get a notification if the boat drifts outside of a predetermined area, if the depth reduces to a critical figure, or if the heading changes by more than a set amount.
A premium service allows devices such as refrigeration, heating, lights and so on to be controlled remotely. This is done through relays, so the boat doesn’t need to have a digital switching system. Additional sensors, such as a contact sensor on the main hatch, or a bilge alarm, can also be added.
Vesper has tried to make the product sufficiently flexible to be used on a wide variety of craft, from small RIBS to superyachts, in which up to ten handsets can be connected. But what else does the system have the potential to do?
“The key is that it’s a platform,” says Forbes. “We will continually develop it and add extra features – there’s a lot of untapped power in the hardware.”
AIS developments – Class B+
SOTDMA Class B units, which are sometimes referred to as Class B+ or Smartais, sit between the original Class B transceivers and the more powerful Class A units that commercial vessels are required to fit.
Fundamentally, they offer more frequent and more reliable updates, along with significantly greater output power.
These factors can be particularly useful on a boat voyaging longer distances and for those which travel at faster speeds. In today’s world that can just as easily apply to offshore racing yachts and to larger cruising boats as to power driven vessels.
Standard Class B units transmit roughly every 30 seconds, but if the frequency is busy they must wait for a gap in transmissions from vessels equipped with Class A and Class B SOTDMA units. By contrast, a SOTDMA (Self-organised Time Division Multiple Access) equipped AIS will claim a short (26.6 millisecond) timeslot in advance – it’s a system that allows up to 4,500 craft to be accommodated on AIS frequencies.
In addition, as the speed of a vessel equipped with Class B SOTDMA increases, so does the rate of transmission. This in turn enables more accurate calculation of the Closest Point of Approach (CPA) and Time to CPA.
Standard Class B units have only 2W of transmission power, which limits range to a maximum of around eight miles. In practice many boats have losses in
VHF cables or antennas that reduce AIS range to a fraction of this figure. Class B SOTDMA units output 5W, which extends range to 16-20 miles. The signal is also strong enough to be received by satellite, which has obvious benefits for friends and family onshore wanting to track a vessel using services such as Marine Traffic.