One of the priority tasks for Metstrade this year was to finalize a monitoring system (both onboard and remote), including logging and alarms

One of the priority tasks for Metstrade this year was to finalize a monitoring system (both onboard and remote), including logging and alarms. With electric systems, at least the choice of brand is clear — Victron has almost monopolized the market by offering a modern, owner-friendly product that’s easily scalable and has a well-defined architecture. But with monitoring, the situation is very different. There are Digital Yachts, Sensare, Sailsense, YM Sentinel, Sentinel Marine, and others. Some are widely used by shipyards or charter companies to monitor fleets and handle warranty cases, yet as far as I know none of them has become popular among private boat owners.

Typically, when you approach any of these companies, the first thing they tell you is that they have built-in GPS, battery and tank monitoring, and shore-power alarms. The problem is that all of this is already well covered by the Victron Cerbo GX. It’s cheaper, it controls all Victron equipment onboard, and any modern, well-engineered medium-size yacht will already have it.

So, what exactly do we want from a third-party monitoring system that Victron does not offer?

Logging. We want to know if the bilge pump has been running constantly in the last days — and ideally, whether it was pumping water or running dry. We might be curious about historical wind or boat-speed data. We may want an alarm if our boat speed constantly differs from SOG, meaning that our calculated wind data are also wrong — the same goes for other navigational data.

Self-diagnostics. This is something cars have had for 20 years, yet boats still don’t. A self-check on demand — or automatically at engine start — for navigation lights (you still walk to the next pontoon to check the masthead lights, right?), NMEA2000 health, bilge-pump diagnostics, etc.

Maintenance schedule. Based on NMEA data for engine hours, together with a predefined maintenance plan, we’d like to receive reminders for engine service, watermaker service, and so on.

Security. It would be great if the same system included integrated security sensors and cameras.

Scalability. Most monitoring hubs offer just 3–5 analog inputs, while the 70-footer we’re building now has six bilge pumps alone, not to mention other sensors.

Communication. Of course, everything must be monitored remotely, so we need a communication module (GSM, Wi-Fi, satellite).

We want this system to be reliable, we won't go for untested custom solutions. And importantly, the monitoring system must be powered independently from the rest of the boat’s electronics. Some systems, like Digital Yachts, are powered via NMEA2000, which is not convenient when you leave the boat.

At the moment, the system that looks the most complete and well-supported, with a good interface, is probably YM Sentinel. It has independent power, logging, alarms, maintenance reminders, and its own set of security sensors. Unfortunately, none of these “integral” systems has proper self-diagnostics. You can combine a Lopolight hub for navigation-light monitoring and a Digital Yachts module for NMEA, but having several independent systems doesn’t make the boat simpler or safer.

However, during my last round through the stands, I discovered that Sensare has one very important feature: in addition to an eSIM, it offers a small external satellite antenna (about half the size of a mobile phone). It only switches on briefly to send a small update or an alarm, consuming almost no energy — incomparable to Starlink. Subscription costs €140/year or €240 for two years. And this is currently the only realistic way to keep a boat connected outside GSM coverage while keeping standby power consumption very low.

With the new expansion hub, Sensare can monitor five battery banks, two bilge pumps, shore power, fire alarms, and NMEA data when the system is awake for logging and maintenance. It’s not as sophisticated as Sentinel, but it’s good enough to give you peace of mind when you leave your boat far away in some paradise.