VESSEL REVIEW | Alcyon – New tour boat for trips around France's Calanques National Park

ODC Marine recently delivered a new hybrid sightseeing vessel to Icard Maritime, a French tour company that operates primarily in the Calanques National Park off the coast of Marseille.

Designed by Mer et Design, the 19.7-metre (64.6-foot) Alcyon will focus on short- to medium-duration tourist excursions, typically involving several rotations per day. These operations include harbour departures, coastal navigation at moderate cruising speeds, scenic cruising phases, and regular returns to port.

“This operational profile requires frequent manoeuvring, repeated berthing operations, and efficient passenger embarkation and disembarkation throughout the day,” Stéphane Gonnetand, Co-Founder and CEO of ODC Marine, told Baird Maritime. “As a result, she has been designed for intensive daily service, where reliability, punctuality, and ease of operation are essential.”

Gonnetand added that particular attention was given to smooth passenger flow, crew efficiency, and operational robustness, ensuring consistent performance across successive trips while maintaining a high level of comfort for passengers.

Emphasis on performance, capacity and comfort

“The owner’s brief for Alcyon was both clear and ambitious: to deliver a high-capacity passenger vessel capable of combining environmental performance, operational efficiency, and a premium passenger experience, while fully complying with French Regulation Division 223b.

A key requirement was the integration of a hybrid propulsion system allowing full-electric, silent and zero-emission operation in coastal and environmentally sensitive areas. At the same time, the vessel needed to achieve an optimised cruising profile, significantly reducing fuel consumption and operating costs compared to conventional propulsion solutions.

To that end, ODC Marine developed a hybrid propulsion setup consisting of two Cummins QSL9 450hp (340kW) diesel engines, ZF gearboxes, 80kW electric motors, and a 125kWh lithium iron phosphate (LFP) battery pack. This allows the vessel to operate in full-electric mode, delivering silent, vibration-free and zero-emission navigation for up to three hours at 5.5 knots. This capability is ideal for harbour manoeuvring and for operation in environmentally sensitive and protected coastal areas.

“The owner required excellent stability, smooth motion, and very low noise and vibration levels, as well as efficient passenger flow,” said Gonnetand. “These expectations directly influenced key design choices, including an exceptionally wide beam for the vessel’s length, generous deck spaces, a bright and naturally ventilated saloon, and full PMR [personne à mobilité réduite, i.e., person with reduced mobility] accessibility, with dedicated boarding arrangements and sanitary facilities.”

The brief also focused on ease of manoeuvring and crew efficiency. This led to the integration of dual side control stations, a large and ergonomic upper deck wheelhouse, and a general layout designed to simplify embarkation, disembarkation, and daily operations.

The side control stations help improve manoeuvring precision and safety during docking and close-quarter operations, while the air-conditioned wheelhouse – which Gonnetand said is generous in size for a vessel of this category – provides enhanced visibility and working conditions for the crew even during the summer and winter months.

“Finally, the owner was seeking a vessel that would reinforce the operator’s brand image and offer operational flexibility for different activities, including tourism and diving operations. Alcyon was therefore conceived as a future-proof, versatile, and environmentally responsible passenger vessel, fully aligned with the owner’s operational and strategic objectives.”

Configured for economical cruising

Inside the passenger saloon, seating consists of high-comfort stretched fabric seats, providing ergonomics and durability for intensive daily use. These are complemented by long aluminium benches finished with Flexiteek 2G to combine a contemporary marine aesthetic with robustness and ease of maintenance.

“The saloon benefits from natural light and natural ventilation, creating a bright and welcoming environment for passengers during coastal excursions,” Gonnetand told Baird Maritime. “Overall, the interior fitout has been conceived as a practical, accessible and durable solution, perfectly adapted to intensive tourist operations in a coastal environment, while maintaining a high standard of comfort and finish.”

The vessel’s propulsion system meanwhile provides a high level of operational flexibility, combining low-speed electric operation with efficient diesel cruising (for faster coastal passages and schedule-driven operations), while remaining simple and intuitive for the crew to operate.

“Alcyon’s maximum loaded speed is approximately 18 knots, while the operator favoured an optimised cruising speed of around 12 knots, where fuel consumption is reduced by nearly two-thirds compared with operation at maximum speed,” said Gonnetand. “This operating profile significantly lowers environmental impact while improving overall economic efficiency.”

Continuous coordination for integration of hybrid propulsion and a wider beam ideal for moderate speeds

Gonnetand explained that designing and building Alcyon confirmed several key principles that now directly inform future developments at ODC Marine. Firstly, the project reinforced the importance of early and tightly coordinated integration when working with hybrid propulsion systems.

"Combining high-power diesel engines, electric motors and a large LFP battery pack within an all-aluminium structure requires close alignment between structural design, mechanical installation and electrical architecture from the very first design stages. This approach ensures safety, maintainability, regulatory compliance and long-term reliability — and it is now a core methodology for all our hybrid projects."

Alcyon also demonstrated the value of wide-beam hulls when properly engineered. Gonnetand said that while such proportions require strict control of structure, tolerances and weight distribution during construction, they deliver clear operational benefits, namely, superior stability, higher passenger capacity, and improved comfort.

This experience has strengthened ODC Marine’s confidence in developing vessels optimised for efficiency and comfort at moderate cruising speeds, rather than chasing maximum speed.

“Another major takeaway was the critical role of acoustic and vibration control in passenger satisfaction. Achieving very low noise and vibration levels — particularly in electric mode — is not the result of a single solution, but of consistent attention to detail across foundations, insulation, system isolation and commissioning. This holistic approach is now systematically applied across our builds.”

The project also confirmed that it is possible to combine robustness, ease of maintenance, and a high level of finish on a working passenger vessel, provided that materials and systems are selected with long-term operation in mind. Durable solutions such as aluminium seating, decking, and integrated safety equipment allowed ODC Marine to deliver comfort and aesthetics without compromising reliability.

“Overall, Alcyon validated a design philosophy based on refined simplicity, energy efficiency per passenger, and collaborative project management – principles that now underpin ODC Marine’s next generation of passenger vessels,” Gonnetand told Baird Maritime.