Definition
An electric engine, in tender context, is a battery-powered driveline that turns a propeller, sterndrive, or pod through an electric motor rather than an internal combustion engine. It runs silently, emits no exhaust at the point of use, and has become the default choice for short-range day tenders where range is not the constraint.
Background and use
The viable electric tender market sits in two zones. The first is small day boats: 5-7m open or limousine tenders carrying four to six guests on harbour shuttles, hotel transfers, and short coastal hops. Builders such as Candela, X Shore, Frauscher (Times Square electric variant), and Vita have credible products in this segment, with usable ranges of 25-50 nautical miles at 20-25 knots and recharge times of one to four hours from a fast charger. The second zone is jet-tender duty cycles where individual runs are short and the boat returns to a charging berth between trips; Williams and a handful of bespoke builders offer electric jet tenders.
Where electric struggles is the long-range, high-speed envelope where chase boats and offshore tenders operate. A 30-knot, 200-mile day at sea remains a diesel or petrol problem; battery energy density is not yet at a place where the weight penalty is acceptable. Hybrid drivelines (covered separately) bridge the gap.
The infrastructure question is the practical limit. An electric tender needs shore charging or onboard charging from the mothership. Most modern superyachts have 400V three-phase available at the swim platform and can support fast charging, but older yachts and many cruising destinations cannot. Specifying an electric tender without a documented charging plan is a recipe for an idle boat in the garage.
Related considerations
- Always confirm charging compatibility (voltage, amperage, connector type) between tender and mothership.
- Battery degradation is real; expect 20-30% capacity loss at five to seven years depending on charge cycles and thermal management.
- Insurance for lithium-ion battery installations is tightening; check that the tender's battery system meets your underwriter's requirements.
- Resale market for electric tenders is still maturing; specify with a longer ownership horizon in mind.
- Onboard auxiliary loads (heating, cooling, navigation) draw from the same battery; published range figures often assume minimal hotel load.