Samurai is the image of this boat. A Samurai traditionally has been a person who serves a well respected leader and has “Busido” spirit meaning they have the drive to fight with every effort and dedication to the best of their ability and skill.

The K36-SAMURAI is a light-weight high performance boat which has been seriously and dedicatedly optimized using an objective scientific approach utilizing rigorous performance studies. To achieve the “Busido” spirit in the K36-SAMURAI ACT, SDK Structures and Pauger Carbon Ltd have teamed up to produce all carbon boat of the highest quality.

Principal dimensions:

Loa 10.88m
Beam 3.59m
Draft 2.45m
Displacement 3100kg
Ballast 1550kg
Mainsail 49.5m2
Spinnaker 145m2
I 14.35m
J 4.42m
P 14.75m
E 4.85m
STL 6.60m
Jib sail 34.3m2
ACT Co.,Ltd.SDK Structures, LLCPauger Carbon Ltd.

Boat concept

The K36-SAMURAI is a light-weight high performance boat designed to fit into the HPR (High Performance Rule) class of racing yachts. Suitable for both inshore around-the-buoys and offshore long distance races the design is targeted to a race oriented owner who wants to enjoy fast and fun sailing more easily and effortlessly and at a more reasonable cost than with a 40 footer race boat. The performance has been intensively studied to also be competitive under the ORC and IRC rating systems.

Although it is true that light-weight high performance boats have relatively higher ratings compared with heavier cruiser-racers especially in the medium winds around 12kts, the unfavourable difference will be a few percentage of the rating and can be overcome by the significant performance improvements available in a modern light-weight design. It is also true that the high performance boats can provide much better performance in light winds and in planing conditions and therefore get tactical benefits by sailing ahead of other boats in the fleet.

The K36-SAMURAI design benefits from ACT’s extensive CFD experience of over 20 years in the America’s Cup, with other classes of racing yachts, and also in the competitive commercial ship market, which similarly requires significant performance improvements. CFD is one of the technologies often utilized for scientific design but to achieve useful results it requires careful technique and years of experience. This technique and experience have been applied to the hull shape and appendage configuration of this new design. The hull shape has been intensively refined to have lower drag in combination with stability and power and has been evaluated by CFD at various boat speeds in downwind, including planing conditions, and in multiple upwind heel and leeway conditions. A total of more than 300 cases design simulations were run to finalize the shape. The keel position was optimized to achieve the best trim over a wide range of wind conditions by considering the changing of LCG position with varying crew placement. The rudder position was studied to give good yaw balance and enough lift force to enable easy handling.

The specifications were determined by careful study of the VPP results, consideration of the applicable rating systems, and comparisons with multiple recent HPR designs. Draft is not too deep to maintain access to relatively shallow marinas and the maximum beam was chosen to keep the stability well balanced with the sail plan and displacement, all of which will provide benefits under the ORC and IRC rating systems.

The deck arrangement was designed to be as simple and spacious as possible with crew ergonomics considered over a range of crew positions to allow optimal fore-and-aft trim. All control lines except vang line are led above deck without any holes into the interior to avoid water intake keeping the interior dry for both comfort and to avoid unnecessary weight.

To achieve the best structural arrangement for a light and stiff hull SDK Structures LLC has drawn upon their extensive experiences in light-weight high performance race boats engineering. Structural ideas have been borrowed from the competitive TP52 and Maxi 72 classes and scaled down to suit a 36 ft yacht. The structure is designed to satisfy the ISO Category A and ISAF OSR Category 1 to ensure years of competitive racing in potentially rough conditions.

The Pauger Carbon Ltd is the builder for both of the boat and rig. Pauger has years of experience in building both carbon composite racing yachts and high performance carbon rigs. Drawing on this experience they are infusing the hull and deck in female molds using high strength carbon fiber and Airex structural foam core. The interior structure is also of carbon and foam and the majority of the carbon is unidirectional material for optimal strength, stiffness, and fiber content. The keel fin is fabricated of high tensile steel with composite fairings to provide a low VCG.


Principal dimensions
P = 14750
I = 14350
J = 4420
E = 4850
STL = 6600
Main Sail area = 49.5m2
Jib Sail area = 34.3m2
Spin Sail area = 145.0m2


Principal Dimensions
Loa 10.88m
Beam 3.59m
Draft 2.45m
Displacement 3100kg
Ballast 1550kg
I 14.35m
J 4.42m
P 14.75m
E 4.85m
STL 6.60m
  • All structures are carbon-epoxy construction and built in accordance with the ISO12215 Category A
  • Female hull mould created from high-precision CNC machined plug is used for lamination
  • Carbon-epoxy hull and interior structure in sandwich construction with foam core by vacuum infusion technology
  • White gel coated finish (alternative option: Durepox painted finish)
  • Female deck mould created from high-precision CNC machined plug is used for lamination
  • Carbon-epoxy deck in sandwich construction with foam core by vacuum infusion technology
  • Bow toe rails included in the mould
  • Chainplates fitted
  • Companionway hatch and wash board
  • White gel coated finish (alternative option: Durepox painted finish)
  • Stick-on non slip on cockpit and painted non-skid on deck
  • Welded steel fin with composite fairing
  • Lead bulb
  • Epoxy primer finish
  • Carbon blade
  • Female rudder blade mould created from high-precision CNC machined plug is used for lamination
  • Carbon shaft
  • Top and bottom roller bearings
  • Carbon tiller
  • Epoxy primer finish
  • Emergency tiller
Deck gear
  • 2×2speed Harken primary Harken winch (46.2STP)
  • 1×2speed Harken pit Harken winch (40.2STP)
  • 2×2speed Harken mainsheet Harken winch (40.2STP)
  • 2×2speed Harken backstay Harken winch (35.2STP)
  • Lewmar foredeck hatch
  • 5×Clutch
  • 4×Mast turning halyard block
  • 2:1 mainsheet control system leading from the track end to mainsheet winches
  • 6:1 traveler control system
  • 16:1 outhaul system
  • 2x3:1 backstay control system leading to backstay winches
  • Vang control system
  • Mainsail cunningham system
  • 10:1 Jib in/out system with transverse tracks
  • 14:1 Jib up/down system
  • Bow pole control system
  • Tack line system
  • Geneker sheet system
  • Kite takedown system
  • 2×cockpit inspection hatch
  • Stainless steel stanchions, pulpit and pushpit
  • Stainless steel lifelines
  • Tiller extension
  • 4×pipe cots
  • FRP sink with hand pump
  • Bladder fresh water tank
  • Twin burner gimbaled cooker
  • Flush toilet
  • Navigation table
  • Manual bilge pump
  • Yanmar 3YM20 SD20
  • 2 bladed folding propeller
  • 40L Plastic fuel tank
  • Exhaust system with water lock
  • Removable engine box
  • Control panel with rev counter and alarm in cabin
  • Throttle control in cockpit side wall
  • Electrical switch panel with 12V supply
  • LED cabin lights
  • LED navigation lights
  • 2×12V battery and main switch
Spars and Rigging
  • Carbon fractional mast
  • Twin swept back spreaders
  • Rod standing rigging
  • 2 groove Harken headstay foil
  • Carbon boom with 3 sheaves
  • Retractable carbon bow pole
  • Carbon solid vang
  • External jack system

Specifications are subject to change without advance notice.


The first two boats were launched in Hayama, Japan in March and May 2016. The third and fourth boats are under construction as of 5 Oct 2016.