How do you make your boat easy to control, from any screen on board or even remotely and save weight? Sam Fortescue talks us through digital switching

Just imagine this. As you graze a sandwich at your desk one Friday, you flick open an app on the phone to check what the wind is doing on the mooring. The boat briefly fires up the instruments to give you real-time data, before powering them down again. A balmy 12 knots, just as forecast. It’s the green light for a weekend sail.

As you jump on the train down to the marina, you fire up the app again, checking battery and fuel levels. There’s still a trickle of power coming out of the solar panels, and the wind turbine is doing its job in the breeze, so no need to start the generator yet. You switch the fridge on instead – it’ll be down to temperature by the time you arrive.

Checking another app shows that the tender is just where it should be in the dinghy dock, with the outboard also present and correct. It’s only a few hundred metres upstream to the mooring – an easy ride for the electric outboard. As you round the last bend in the trot, you press a button on the key fob. Lights in the cockpit, rigging and at the transom wink on, and the instruments spring to life.

The multimedia unit starts piping the relaxing tones of your favourite song into the cockpit, and the alarm is deactivated. The bathing platform lowers into position for an easy landing.

Well, imagine no longer, because all this is already possible.

It might sound far-fetched, but boats are already being built with these capabilities, thanks to digital switching and remote monitoring. And, as with most innovations at sea, they are trickling down from the elusive world of superyachting.

The digital switching screen on the Bavaria C50 gives control over a whole range of systems

Digital Control

If you buy a new boat today, the chances are it contains some form of digital switching. More than just a different sort of on/off button, it is a powerful way to control boat systems that is built around a flexible network. Or, as Nick LaRoche of US-based PowerPlex describes it: ‘Fuses, mechanical circuit breakers and switches are replaced by a digital switching power distribution system that runs on a CAN (Controller Area Network) bus network.’

Now, weight is a clear benefit of digital switching, in that you don’t need hefty two-pole wire runs between switch panels, toggle switches and the equipment itself. The switch can be anywhere and the unit can be anywhere as long as they’re all plugged into the CAN bus. In effect, you simply need a 12V/24V ring main and a CAN bus backbone running around the boat.

Digital switch modules located near the equipment itself then plug into power and network with very short cable runs. On a 30-50ft sailing boat, the saving in copper alone amounts to tens of kilograms, even including the extra weight of the control modules.

Growing list of advantages

In the early days of this technology, it was thought that factors such as weight and space were chief among the key advantages. Brands such as New Zealand’s C-Zone (now a Brunswick brand alongside B&G) and Sweden’s Empirbus (Garmin), grew on the back of such claims.

‘Our main benefits used to be related to weight and space saving, installation time saved for builders,’ says Mark Harnett of C-Zone, one of the three major digital switching brands for boats. ‘But this message has changed in recent years to ease of use.’ That’s because each element in a digital switching network is independent and can be programmed to behave in whatever way you wish. You can set dimmers, time switches, high and lower power actuators. The touch of a single button could set multiple actions in motion – creating a mood on board, or readying the boat for sea or swimming.

Turn on the lights before you arrive at your boat. Photo: Morten Strauch

Similarly, the displays that provide the user interface are very flexible. You can install a dedicated display from C-Zone, Empirbus or similar. Or you can just use your existing plotter.

Manufacturers like B&G, Raymarine and Garmin have all built support for digital switching into their multifunction displays, so you can be panning through charts one moment and putting on the navigation lights the next – all from the same touchscreen display.

This is a very efficient way to provide digital controls, especially in a scenario where the boat already has more than one display – perhaps at the chart table and at the helm. ‘The cost of displays and control units at the dash or chart table can be reduced, as CZone can control things like power electronics and batteries, monitor tanks, control audio and heating/aircon,’ says CZone’s Harnett. ‘This can remove multiple redundant controllers and allow interaction between these devices, at the same time the user gets the benefit of a single user interface to learn, instead of having to get to grips with multiple.’

Numerous long wiring runs add significant weight to a boat, which CAN bus switching can mitigate.

Getting digital switching

This technology is very much a means to an end, a tool that is perhaps not often glimpsed in its own right. If you look behind the scenes of Hanse and Moody sailing boats, you’ll find C-Zone switching. Oyster yachts and the composite wizards at McConaghy also use it.

This breadth of use from production yachts to custom one-offs is possible because the system is modular, so it can be as complex or as simple as you need. The first hint you’re likely to get that a boat features the technology is from the control panel or plotter. If there is a natty-looking display with touchscreen switches, then you’ve got it.

For the rest of us, there is a refit route to digital switching which can make sense, ‘especially if you are doing a more extensive electrical systems refit’, according to C-Zone’s Harnett. For smaller boats, there are entry-level modules at lower costs.

For CZone, that means the Contact 6 (£380), which is able to switch six different loads on or off up to 7.5 amps. In addition to the control screen on the MFD, a host of keypads (from £250) with custom labelling can give remote control over key functions without the need for a dedicated display or networked plotter.

Raymarine takes a slightly different approach with its new YachtSense. It is aiming for more ambitious refits, with a modular approach that was built out of the Empirbus system.

A master unit neatly plugs into slivers of whatever additional switching units you need – low power, high power, reversible motor and signal. In this neat package, you can control and oversee every circuit on board, but it comes at a price: €995 (£867) for the master controller and €395 (£345) for each additional sliver.

Since Garmin took EmpirBus in-house, the system has been reoriented towards the manufacturer’s own plotters, which naturally enough offer the greatest customisation and control options. But the system will still integrate with any plotter system from Raymarine, B&G or Furuno.

Empirbus is built around a master control unit which activates different modules around the boat. Prices are not published, but they are comparable with Raymarine.

For smaller boats looking to retrofit some form of digital switching, Garmin has developed the Empirbus hardware into an all-in-one unit called the Boat Switch. It plugs straight into the NMEA2000 system for chartplotter control, and you can run up to 20 circuits off it, on either 10- or 5-amp channels. At £950, this is an efficient approach if you already have a Garmin instrument system.

Or you could use the SailSense PowerRail (ca. €2,520/ £2,196), which can control 24 circuits up to 16A, 8 sensors and 3 battery banks. Both of these systems are centralised and require the full run of cabling from the unit to the load, as in a traditional set-up.

The new Oyster 495’s helm pod gives you a smorgasbord of control without leaving the wheel. Photo: Morten Strauch

Alternative brands

There are other brands as well, but they are often focused on market niches. Italy’s Blink was in the vanguard of digital switching, and provides keypads to the America’s Cup campaigns of both Luna Rossa Prada Pirelli and Emirates Team New Zealand, as well as to rally drivers. Its simple Keybox product has been hugely successful in the US, where it is retrofitted as a replacement for defunct DS (disconnect standby) switches.

Yacht Devices has a handy 4-channel control circuit, which plugs into a NMEA 2000 network and can be used on any plotter with support for CZone. The YDCC-04 costs £249 and its four-load capacity can be doubled by adding a £119 additional control post.

In the future

As with everything in life, digital connectivity is becoming more deeply embedded. All the manufacturers I spoke to were reluctant to divulge future plans, but they all looked to the automotive and domestic markets as pathfinders for digital switching and the internet of things aboard.

At the moment, it is all about functionality – allowing us to do things remotely and easily using a single interface. ‘We believe the digital ecosystem will grow to include “off
the vessel”, and that users will have access to their onboard systems from anywhere through a mobile experience,’ says Harnett. ‘A single common user interface across multiple platforms like phones, tablets, on board multifunction and navigation displays is essential for a best-in-class ecosystem.’

Raymarine, like other brands, builds digital switching functionality into all of its multi-function display (MFD) chart plotters

This way, interested guests are able to look at charts, tracks and instrument data from the boat via their phones. ‘A connected phone or tablet becomes an additional display presenting data from the plotter,’ says Peter Ingram of Raymarine. ‘Guest crew can look at the charts for position and help with depth monitoring. It offers a more inclusive experience if the captain invites them to the network.’

Integration with companion apps to the big three instrument makers (Raymarine, Navico and Garmin) will make it easier to export some of this information for sharing
with those not on board.

As boats become more automated, with electric winches, in-mast furling and magic trim (the new Oyster 495, for instance, trims the main using a hydraulic ram in the boom), it will become more logical to control these systems via a single unified touchscreen display. It will also be more common to have fuel, water and waste tanks digitally monitored, and for valves, switches and pumps in everything from electric heads to watermakers, solar panels to generators reporting to and controlled from the display.

Centralised control means you only need to learn how to use one operating system, rather than lots of separate ones

Integrated coding

Key to getting all this in place is for different manufacturers to open up the coding behind their own controllers so that it can be integrated. At the moment, there is limited compatibility between different brands. Take CZone and Mastervolt, for instance. Both owned by Brunswick, and both using a CAN bus to talk to their network, yet you need to buy a dedicated black box ‘translator’ in order to get them talking to each other.

Dave Dunn, senior sales director marine at Garmin, says that integration is the buzzword of the moment. ‘There’s more integration going on than ever before – from lighting to powershades,’ he says. ‘Lighting is very popular because you can get more customisation, but also pumps, gensets (generators) and so on. It’ll be like a smart home – you push one button and several things happen.’

Despite all the buzz about modern NMEA 2000 systems, this form of CAN bus is a mid-bandwidth form of communication – ideal for limited sensor data and status reports. Functions such as radar and advanced sonar generate more intensive data, so they run over Ethernet. But even here, manufacturers are beginning to feel constrained.

Ethernet standards have been upgraded over time, so the old category 5 systems, which were capable of transmitting 100Mbps, have been superseded by category 6 with up to 100 times the speed – that is, a blistering 10Gbps.

CZone’s system works well on small as well as large boats

Network upgrade

Now, most of us will never be troubled by this distinction, because our instrument networks amount to one or two MFDs, a radar and a perhaps a basic sonar. This is well within the capabilities of category 5 Ethernet.

But superyachts are another matter, and where the top end of the market leads, the rest of us follow. ‘If these systems are going to get bigger and faster and smarter, we’re going to need a new network backbone,’ says Dunn. ‘It’s at the very high end, but it will start to trickle down. Higher bandwidth will open up the doors to tablets and wireless communications, with wireless wind transducers and wireless sonar. Higher bandwidth will allow these systems to be more reliable.’

NMEA has an answer to this, called OneNet – a high powered Ethernet standard. But NMEA membership is expensive, so smaller manufacturers are tempted to use open source standards instead.

Autonmous sailing vessels are already a reality. Their sensing and control tech will become more commonplace for yachts

Battery and inverter maker Victron has done just that, in the hope that it will encourage others to work with it. And it has signed up as a partner Oceanvolt, one of the key players in electric propulsion and the future of electric boating.

In the end, of course, all this leads in just one direction: automation. The era of the fully autonomous vessel is already upon us, with boats from the tiny 2m Sailbuoy to the giant Mayflower catamaran successfully crossing the Atlantic without human input.

What is not yet possible is for a boat to unmoor itself and motor or sail to meet you elsewhere. But we’re getting to the point where boats, with a skipper aboard, can navigate themselves. ‘Between digital switching and these higher bandwidth systems, you could hypothetically have an autopilot that takes readings from radar and sonar, and makes path predictions,’ says Dunn. ‘With machine learning and AI, it won’t happen in five years, but it could be a 10- to 15-year thing.’

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