Powering Up for a 10 year Circumnavigation

At Crest Marine Services, we pride ourselves on delivering reliable, safe, and creative solutions for complex electrical issues afloat. One of our recent callouts came from the skipper of Shadowfax, a yacht preparing for a ten-year circumnavigation, and just three days from departure.

The problem? The vessel’s inverter wouldn’t run the calorifier’s immersion heater. The setup worked fine from shore power and the generator, but the inverter refused to cooperate, despite the live being properly connected. It was clear this wasn’t a basic fault.

The skipper had already spoken to a few marine electricians, who suspected a neutral issue but declined to get involved. That’s understandable. Neutral faults can be notoriously tricky to diagnose and fix. With a fault on the live, you can easily verify voltage and track the problem. On the neutral side, though, things are far less straightforward. Fault finding gets technical very quickly, and with time running short, mistakes weren’t an option.

After a detailed discussion with the skipper about how the system was originally designed, how it needed to function, and what protections were in place, we got to work. We spent time fault finding and carefully evaluating the wiring setup. Once we confirmed that all necessary protections were present, we re-wired the relevant circuits so the immersion heater could run safely from the inverter when needed.

To help protect the house battery bank, we also installed a timer module — a simple but effective safeguard to prevent the heater being accidentally left on and draining power when underway or at anchor.

We wish the skipper and his family the very best as they begin their ten-year voyage around the world aboard Shadowfax. It was a pleasure to help them get one step closer to departure.

Fair winds and following seas.