Rewire
At Crest Marine Services, we provide professional marine electrical upgrades, rewires, and custom builds to keep your boat safe, reliable, and ready for the sea.
Built on Engineering Principles, Not Guesswork
Before founding Crest Marine Services, I spent several years as an electrical design engineer, working with major companies and household names. The systems I designed were deployed globally in their thousands, you’ve almost certainly seen equipment I’ve worked on, probably today.
Later, I specialised in the electrical design of commercial vehicle modifications, where I was responsible for designing systems for large fleets of vehicles including the largest fleet of vehicles in Europe. My work included bespoke builds for bomb disposal units, mountain rescue ambulances, incident command vehicles, and other specialist platforms most people don’t even know exist—the kind you hope are never needed, but must work flawlessly when they are.
I’m more than capable of wiring your boat from memory and making educated guesses. Many people can do that. But in my experience, that’s not the right way to build reliable electrical systems—especially not for marine environments where failure is more than an inconvenience.
That’s why I approach every rewire with the same design-led mindset: define the requirements, engineer the solution, then build it properly.
Marine Rewires – Our 4-Stage Approach
Over time, the harsh marine environment takes its toll. Saltwater exposure, rolling repairs, and different electricians working on a vessel over the years can leave electrical systems messy, corroded, and difficult to fault-find.
Without clear schematics and consistent workmanship, small problems can turn into long delays when your boat should be on the water.
At Crest Marine Services, we take a smarter, more structured approach to marine electrical rewires. While some marine electricians may spend a week or two tearing out old wiring and installing new cables by memory, we believe there’s a better, more professional way to achieve long-lasting, efficient results.
Our process is broken down into four key stages: Specification, Design, Build, and Installation/Commissioning. This method not only ensures a reliable, custom-tailored electrical system—it also reduces downtime and cost and spreads that cost over a more manageable timeline, giving you flexibility. You’re never locked in: you can take the work to another provider at any stage if you choose.
1. Specification
Every rewire begins with understanding how you use your boat. We gather information about the electrical equipment you need, your preferred usage patterns, charging sources, and battery requirements.
Battery performance is especially complex and often misunderstood. To tackle this, we’ve developed our own marine electrical system specification software. By inputting your data, we can accurately model your vessel’s energy needs and recommend the right battery system. This prevents costly over-sizing, reduces unnecessary weight, and can free up valuable space onboard.
With Crest Marine, you’re not guessing — you’re investing in a system that’s built around your real-world usage.
2. Design
Once we know what the system needs to do, we move on to electrical system design. Here, we plan how everything will work together:
What’s safety-critical
Where to build in redundancy
Cable routing and voltage drop calculations
Fusing, protection, and equipment selection
We create a detailed electrical schematic and harness diagram, making future troubleshooting or upgrades easy. By the end of this phase, you’ll receive a complete design package along with a quote for the build phase. Your free to take this to another supplier to complete the job if you wish.
3. Build
Unlike many providers, we build your wiring harnesses off the boat. This:
Avoids days of disruption onboard
Keeps labour costs down by minimizing time spent doing unskilled work in tight spaces
Allows for cleaner, more precise wiring assemblies
Your harnesses are manufactured to spec, wrapped in loom tape and flexible conduit, and delivered ready to install—no mess, no fuss. Most vessels will use multiple plug-and-play style looms, which we can build and deliver in phases, spreading the cost over time.
When it’s time for a future upgrade, we can plan this from the schematic. To rewire, we simply remake the harnesses from your drawings—no need to redesign from scratch.
4. Installation & Commissioning
Finally, we install and commission the system. Because everything is pre-built and labelled, installation is quick, clean, and minimally invasive. We perform all necessary electrical testing, system checks, and commissioning to ensure your vessel is ready to operate safely and reliably.
We leave you with full documentation, schematics, and ongoing support. The result is a professionally built marine electrical system that’s safe, efficient, and easy to service.
Why Choose Crest Marine Services?
Structured, four-phase process for better results
Custom-built systems designed for how you use your boat
Reduced downtime, disruption and cost during rewires
Future-proof designs with easy upgrade paths
Flexible project stages—no obligation to stay with us through every step
If you’re looking for a professional marine rewire service in Cornwall and the South West, get in touch with Crest Marine Services today.
Custom Builds
We offer bespoke build services to help streamline your electrical installations. From designing and fabricating complete control panels offsite, to building up lithium battery packs, we work to minimise your downtime and maximise reliability.
Offsite fabrication means panels arrive ready for quick, clean installation, making refits and new system builds faster and more convenient.
Our Commitment to Industry Standards
At Crest Marine Services, we adhere to the highest industry standards to ensure your marine electrical systems are safe, reliable, and compliant.
We follow the British Marine Electrical & Electronic Association (BMEA) Code of Practice, which sets the benchmark for quality, safety, and reliability in marine electrical systems. This ensures that our work is completed with the utmost professionalism, meeting the rigorous requirements of the marine industry.
Additionally, we work in accordance with ISO 13297, the international standard for electrical systems on board boats. ISO stands for the International Organization for Standardization, a globally recognized body that ensures products and services meet quality, safety, and efficiency standards. By adhering to ISO 13297, we ensure that your electrical systems are designed and installed with safety, functionality, and longevity in mind.
