Alu Marine periple 50

ATKA – Expedition Sailboat

World Tour / Polar Expeditions / Scientific Missions

Type : Monohull aluminum sailboat with 2 retractable keels
Program : Polar expeditions, scientific missions, offshore sailing
Architect : Berret–Racoupeau Yacht Design
Shipyard : AluMarine (France)
Year of construction : 2001
Hull length : 15.19 m
Width : 4.88 m
Variable draft : 0.80 m → 3.20 m
Material : Double hull aluminum
Autonomy : Large diesel capacity + 5 KVA generator
History : Antarctica, world tour via the southern islands, Arctic, Northwest Passage, Greenland, Svalbard
Current status : Operational vessel, available immediately, located in France

Summary

ATKA is a 15-meter aluminum expedition sailboat, designed from the outset for offshore and polar navigation. A robust, autonomous, easy-to-maintain boat with an exceptional sailing history: Antarctica, world tour through the Southern Seas, Northwest Passage, multiple winterings and scientific campaigns in Greenland and Svalbard.

Built by the AluMarine shipyard based on Berret-Racoupeau plans, it features a double aluminum hull, two retractable keels, two retractable rudders, protected propulsion, retractable and accessible, and a Northern Lights generator providing total electrical autonomy.

Major technical stop (refurbishment) completed in 2024–2025 (€73,000) + new fittings (€37,000)
Safety equipment up to date (raft, life jackets, survival suits).
Onboard scientific equipment (crane, line hauler, sounder, etc.).

Vessel ready to sail immediately.
Visit by appointment with Mahé NAUTIC at +33659846173

1. Identification & main data

• Vessel name : ATKA
• Type : Offshore expedition monohull sailboat
• Program : Polar navigation, scientific missions, offshore adventure
• Naval architect : Berret-Racoupeau Yacht Design
• Construction yard : AluMarine (France)
• Year of construction : 2001
• Model : Périple 50
• Flag : French
• Administrative status : Pleasure vessel for personal use and training
• Certificate of registration : up to date as of 30/06/2023
• Navigation category : Offshore (Division 240)

Main dimensions

Overall length (LOA)

15.19 m

Waterline length (LWL)

13.72 m

Beam

4.88 m

Variable draft

0.80 m → 3.20 m

Light displacement

13.1 t

Total ballast

2.8 t (lead)

Hull / deck material

Aluminum 5083 H111 – full double hull

Sail plan

Sail area upwind

118.8 m²

Mainsail

65.30 m² – dacron – full-batten

Genoa

53.50 m² – dacron – UV protection strip

Jib

on removable stay – dacron

Mast on ball joint

Maréchal Masts profile – mechanically welded aluminum

2. Hull & construction

• Construction: welded aluminum, full double hull
• Shipyard: AluMarine (France)
• Architecture: Berret-Racoupeau Yacht Design
• Alloy: aluminum 5083 H111 (reinforced thicknesses for polar areas)
• Internal structure: frames, planking, and welded stringers
• Integrated tanks in the hull (fresh water, diesel, gray/black water) = structural reinforcement
• Welded non-slip aluminum deck
• Reinforced hull for navigation in ice and ice shelf support
• Complete refit 2025 (new anodes + hull revision + antifouling before launch

3. Appendices

General configuration

• Type: sailboat with 2 retractable daggerboards
• Appendices: 2 retractable keels + 2 retractable rudders
• Variable draft: 0.80 m (high keels) → 3.20 m (low keels)
  Allows navigation in deep waters, shallow areas, controlled grounding, approach to glaciers & ice shelves.

Keels

• Two aluminum daggerboards, ballasted with lead
• Vertical sliding in aluminum wells integrated into the hull and deck
• Operated by winches located at the level of the crossbars
• Independent keels for stability management, reduced wetted surface, access to shallow areas

Rudders

• Two aluminum rudders, mounted on aluminum shafts
• Installed in articulated boxes allowing complete lifting by halyard
• Connected by aluminum coupling bar
• Steering assisted by:
  1. hydraulic cylinder coupled to the starboard rudder lever
  2. double wheel steering system
  3. autopilot via electro-hydraulic pump

Propulsion protection / grounding / wintering in ice

• Appendices system designed for wintering in ice, voluntary groundings, uncharted areas
• Rudders + keels + propeller retractable and accessible = maximum safety in polar areas

4. Motorization

Main engine

• Brand / model : NANNI Diesel N4.115
• Type: 4-cylinder turbocharged
• Power: 115 HP
• Fuel: diesel
• Cooling: seawater / internal circuit heat exchanger (keel cooling)
• Starting & electrical system: 12 V

Transmission

• Shaft line with rigid coupling, connected to a universal joint system allowing the lifting of the shaft line in a well
• Advantages:
  1. ❄️ Propeller protection during wintering in ice
  2. Intervention possible from inside the vessel via inspection wells
  3. Navigation possible in very shallow water without risk to propulsion

Propeller

• 5-blade propeller, accessible from the inside
• Lifting function providing protection against impacts (ice, grounding, floating objects)

Generator

• Brand : Northern Lights
• Power : 5 KVA – 225 V under load
• Cooling: internal liquid circuit circulating in a network of tubes in the hull (keel cooling)
  → Allows prolonged operation in polar environments (no risk of seawater freezing)

5. Energy & Autonomy

Electricity production

• 1 generator Northern Lights – 5 KVA – 225 V
• Cooling internal, independent of seawater (adapted to freezing and polar areas)
• No solar panels, no wind turbine, no hydro generator → controlled, simple, reliable production

Battery bank

• 4 Victron GEL 12 V batteries – 220 Ah
• Installed new in 2025
• Bank housed in ventilated compartment, protected from freezing / condensation

Distribution & charging

• Network 12 V DC + 230 V AC
• Charging via generator and dedicated charger
• Conversion 220 V → 12 V via internal regulation

➡️ Configuration designed for expedition: simplicity, mechanical redundancy, repairability

6. Rigging & Sails

Rigging

• Manufacturer: Maréchal Mât (France)
• Aluminum wing profile mast, internal reinforcements + aluminum spreaders
• Good condition, no signs of cracking or structural fatigue
• Removable stay for jib / storm sail

Sails (Dacron)

Sail

Area

Condition

Mainsail

65.3 m² – fully battened

Good condition, battens & cars OK

Genoa

53.5 m² – UV protection strip

Fair condition, normal wear

Jib

on removable stay

Fair condition for use

Storm sail

available

not recently used

➡️ Sail set adapted to the polar program: quick reduction, strong wind handling, reliability of dacron

7. Safety & Survival Equipment

Individual equipment

• 7 automatic CrewFit life jackets – renewed 2025
• 7 SOLAS Endurance immersion suits
  1. 6 renewed in 2024
  2. 1 renewed in 2025

........ Complete file available upon request with Mahé NAUTIC.