New display
A common addition to an older electronics network is a new repeater display, perhaps in the cockpit or at the chart table. It is far cheaper than a more powerful MFD, but you will very likely face many of the same issues with connectivity.
New instrument displays like B&G’S Triton2 and Raymarine’s i70s will invariably use the more recent N2K standard, so to view speed or depth data from your old instruments you will need to convert it from N0183 to N2K, using one of the gateway devices mentioned in Scenario 1 on page 39. If there are multiple N0183 instruments, you may also need to add a multiplexer.
Once again, you are effectively creating a mini N2K network on your boat in order to use the display. At its simplest, that means installing a short length of backbone with a T-piece node for the new display, another node bringing power in from the battery and a third node connecting the NMEA converter. The benefit of this construction is that the network can easily be expanded in the future with new instruments.
Ben Holdsworth of marine electronics installer Greenham Regis says it is simple to build the network, but cautions against creating too many connections between different instrument groups. ‘Sometimes it’s easy to get yourself stuck in a data loop,’ he says. ‘For instance, if you have an N2K chartplotter and you want to delete a waypoint, that goes into the N2K network and across the converter to the 0183 network. But if you have Seatalk connected as well, you can find that you never actually manage to delete that waypoint. By the time you’ve deleted it, it comes back onto the plotter via a different loop.’ This was the case in a recent job Greenham Regis did on a Swan, where the technicians found there simply wasn’t a sensible way to keep one of the old displays in the system.
If the prospect of a network makes you blanch, then you could consider another option. French manufacturer NKE offers a Multigraphic display that can accept a single NMEA 0183 input. Although these displays are designed to work with NKE’S own suite of more race-oriented sensors on their own proprietary Topline bus, they will work perfectly well with older instruments. It is not a cheap option, though, as these capable displays cost around €1,700. If it is only simple data that you want to display, then Nasa Marine’s multifunction repeater (£289) could be the answer. Note that it doesn’t let you customise pages or set alarms, just toggle through key navigation data.