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Upgrade the Boat You Already Love
Hybrid and electric refit options for existing diesel yachts — explored honestly.
The Question More Owners Are Asking
You've Invested in a Vessel You Know and Trust
The layout works. The range works. You know every system. The question isn't whether to buy a new boat — it's whether the boat you have can deliver a better ownership experience.
For a growing number of owners, the answer is a hybrid or electric refit. Quieter harbor operation. Reduced generator dependence. Lower fuel costs on the passages you actually do. The technology that powers purpose-built hybrid yachts like Greenline is increasingly available as a retrofit — and the economics are more compelling than most owners expect.
This page explains what a hybrid refit actually involves, whether your vessel is a good candidate, and what the realistic economics look like — honestly.
What a Hybrid Refit Actually Involves
Three Levels of Upgrade
A refit isn't a single product. It's a range of upgrades that can be added incrementally or as a complete system.
Hotel Load Upgrade
Replace your existing battery bank with a lithium-ion or lithium polymer system paired with a high-capacity inverter/charger and solar panels. No propulsion changes — just eliminating generator dependence at anchor.
What it delivers: Silent anchoring, 230/120V without running a diesel generator, solar-assisted recharging. The most accessible entry point and the biggest quality-of-life improvement for most owners.
Typical: 24V–48V systems, 10–50 kWh
Parallel Hybrid
An electric motor/generator integrates into the existing shaft between the diesel engine and gearbox — the same parallel hybrid architecture Greenline uses. Diesel for range, electric for harbor and short-range operation, regeneration while underway.
What it delivers: Electric-only arrivals and departures, no-wake zone operation, automatic battery recharge underway without a separate generator.
Typical: 56V–400V systems, 20–100 kWh
Full Electric Conversion
Diesel engine replaced entirely with electric motors and a large battery bank. Shore power and solar for charging. Zero emissions, minimal mechanical complexity, completely silent operation.
What it delivers: The purest electric experience. Range is constrained by battery capacity — best for defined short-range routes with reliable charging infrastructure.
Typical: 400V–800V systems, 50–150+ kWh
Not Every Boat Is Equally Suited
The best candidates for hybrid conversion share several characteristics. Engine room access, hull type, vessel condition, and your cruising profile all affect what makes sense and what the installation scope looks like.
YSI can help you assess your specific vessel — what would benefit most, what the realistic installation scope looks like, and whether the investment makes sense for how you cruise.
Owners who spend significant time at anchor, in no-wake zones, or on defined coastal routes will see the most benefit. Primarily offshore bluewater passages will see less.
Engine room access — space on the shaft between engine and gearbox for motor/generator installation
Displacement hull — benefits most from hybrid efficiency at slow cruising speeds
Good overall condition — refit makes most sense on a well-maintained vessel with strong remaining service life
Electrical system capacity — larger battery banks require updated wiring, breakers, and shore power connections
Coastal/anchor-heavy profile — Florida, Bahamas, ICW, Great Loop; significant time at anchor or in no-wake zones
The Realistic Economics
What It Costs and What It Returns
Lithium-ion battery bank, high-capacity inverter/charger, solar panels. On a boat running a generator 4–6 hours daily at anchor, fuel and service savings can be meaningful over a 3–5 year horizon. The quality-of-life improvement is immediate.
More complex and highly vessel-dependent. Integration cost varies significantly based on engine room access, shaft configuration, and existing drivetrain. Contact us for a vessel-specific assessment — this one requires a real conversation.
Most transformative result. Range planning is critical and must be assessed against your specific cruising routes before committing. Best evaluated case-by-case with clear understanding of charging infrastructure.
Compare this against the alternative of a new purpose-built hybrid vessel. If your existing boat is in good condition and well-suited to your needs, a targeted refit can deliver many of the same daily benefits at a fraction of the cost. For context on what hybrid ownership looks like over time, see our Greenline ownership cost breakdown.
Propulsion Partners
Systems We Work With
Italian hybrid propulsion specialist offering both parallel and serial hybrid systems engineered for yacht refits and new builds. Integrated clutch systems, variable-speed generators, and high-voltage lithium battery packs designed to fit existing engine rooms without major structural modification. Featured in Professional BoatBuilder and powering production vessels.
e-motion-hybrid.com →Advanced electric propulsion systems with a proven track record in the marine industry. YSI partnered with Ingenity on the delivery of the first all-electric Greenline 40 in North America — a milestone for electric yacht propulsion in the U.S. market.
Read the press release →The inverter/charger and energy management standard across the hybrid boating world. Greenline uses Victron on diesel models to manage the 12V LiFePO4 house bank that powers hotel loads through the inverter — meaningfully reducing generator dependence without propulsion changes. Proven, well-supported, and widely serviced in U.S. markets.
Large-format hybrid propulsion refits use lithium-ion or lithium polymer battery packs ranging from 11 kWh to 150+ kWh at system voltages from 56V to 800V depending on the architecture. Battery management system (BMS) integration is critical — managing cell balancing, thermal protection, and charge/discharge limits. Specified based on electric range goals, hotel load requirements, and engine room constraints.
We're Not a Refit Yard. We're Your Guide.
YSI is not a refit yard — we're brokers and dealers who understand hybrid technology in depth and can help you navigate the decision intelligently.
We're not going to push you toward a refit if a new boat makes more sense. And we're not going to push you toward a new boat if your existing vessel can be upgraded cost-effectively. The right answer depends entirely on your situation.
Assess whether a refit makes sense for your specific vessel and cruising profile
Connect you with qualified refit yards and systems integrators in South Florida and beyond
Advise on which systems make sense for how you actually cruise — not just what's technically possible
Help you think through the economics honestly — including when a new Greenline might be the better answer
Show you Greenline's factory-integrated hybrid system as a reference point — sea trials available from Fort Lauderdale
Also Consider
Purpose-Built Hybrid From the Ground Up
If you're at a stage where a new vessel makes sense, Greenline Yachts offers the most fully integrated hybrid propulsion system in the cruising yacht market — designed from the keel up around the hybrid experience. Every model from the 39 to the 58 Fly is available with the 6G H-Drive hybrid system. At least six Greenlines have completed the Great Loop. The factory-integrated system simply performs differently than any retrofit.
Talk to Someone Who Knows the Technology
Whether you're evaluating a hybrid refit for your existing vessel or deciding between a refit and a new Greenline, we can help you think it through — honestly.