eD-TEC 32 C-Ultra

With its unique twin-drive system, the eD-TEC 32 C-Ultra is stretching the boundaries of green power.

Aiming to make the electric performance RIB a more realistic offshore option, the eD 32 c-Ultra offers a 50-knot top speed and a 30-knot cruising capability. The first carbon-fibre boat, having just been launched in Germany, is driven by eD-TEC’s revolutionary surface-driven eD-QDrive 1 propulsion units and fed by the eD-Technology Stack and battery pack system. It is a set-up that has the electric motor inboard, and the gearbox and ancillaries outboard. Measuring 9.5m in length, with a 3.2m beam and just a 0.84m draught, this RIB is perfect for close inshore work. It is also available with an optional ‘jet thruster’ system, negating the low-speed berthing handicap from which surface drives inevitably suffer.

Each drive is driven by a 100kW motor with a limited 200kW boost facility, enabled by a high-discharge battery bank. The current battery bank is 100kWh, which eD-TEC calculate provides a 30-mile range at a 30-knot cruising speed. However, recent trials have shown that this boat could achieve 40 miles at 25 knots, so the company’s R&D has not been far off the mark. A larger 140kW battery is due for release this summer, so we will likely see this as an upgrade or OEM fitment, with range increasing to 56 miles at 25 knots. Further modifications to the drive system are also anticipated, which will further improve efficiency, so the final production boat should have longer cruising legs than most electric boats to date.

The drive is designed to be a sealed plug in unit.

The drives are mounted through the transom using a quick-mount frame and can be easily removed and installed without any of the fuss involved with conventional inboard installations. The forward end of the unit offers a power-in socket, two 24V sockets for trim tabs and foil actuators, and two CAN bus connectors, making the drive plug-and-play. All other components – the motor, seawater inlets/outlets, motor controller, high-torque gearbox, and humidity, vibration and temperature sensors – are integrated into the drive unit. Consequently there are no additional components to mount, and no through-hull fittings to be added or cut. An interesting aspect is that the hull is ‘foil-ready’, so customers can select a foil-assist system as an option that will extend the range and enhance performance. Thus far, the degree to which the foil assist system will improve hull efficiency has not been stated by eD-TEC, so I suspect this feature has been designed but not trialled.

Surface drives by their nature have always been efficient at speed.

An AI box serves as the system’s brain – not only controlling and optimising the drivetrain itself but also managing the entire 24V and digital switching system on the boat. This means complete on-board integration, which extends to the autopilot and helm electronics. To keep this system future-proof, AI will allow for continual cloud-based remote monitoring, thereby enabling predictive maintenance, OTA software updates for performance enhancements, and automatic remote support and parts supply.

The motor and controller sit inboard while the gearbox sits outside the hull

The design, thanks to the compact nature of the drive system and the fact that there are no outboard engines, means more space aft for leisure, such as the large sun pad, and easy access to the water via a huge bathing platform. The c-Ultra’s unique design and the eD-TEC electric propulsion system make the boat very flexible, as the expansive aft surface area can be repurposed to cater to any number of operational tasks – plus there’s a big forward storage compartment. This first version is targeted specifically at the superyacht and leisure markets.

The helm is certainly clean and clinical

Contemporary luxury is par for the course with a super yacht tender.

The c-Ultra features a central helm console with two seats, a full glass bridge comprising an Axiom 15.6” MFD for navigation, along with a second screen for system monitoring, plus a wired MOB system as standard. There are extensive options available: alternative colours, adding a modular sun pad with two additional forward-facing seats, a head and a shower, a forward console seat, a table and a 36L fridge. From the driver’s perspective, there are various choices: Ullman seating, radar, sonar, autopilot, wireless MOB, an entertainment system, and even solar panels on the hardtop that can be used to run the domestic and entertainment systems. Buyers can also specify additional sun awnings and a performance prop set.

One of the advantages of the compact drive system is a low bathing platform.

Having been developed from the ground up, rather than relying on adapted tech from automotive or other sectors, the eD-QDrive 1 units are pretty unique in the marine sector. They certainly appear transformative in what they offer boatbuilders and boat owners in terms of ease of installation, operation and maintenance. The c-Ultra features not only standard 22kW AC charging but also 150kW DC-DC fast charging, which can charge the batteries from 20% (DOD) to 100% in just 40 minutes, making it ideal for superyacht tender operations. The next stage of sea trials for this boat is scheduled for early summer, so the first turnkey 32 c-Ultras should be on the water before this season ends.