- pure stealth & efficiency -

A modern & highly effective TUNA TROLLING BOAT design, 29m, sail-assisted vessel with steel hull.

Rodney Davidson has combined practical innovations, ergonomics  & smart design

to provide a vessel which greatly improves .......

  • trolling stealth and noise reduction
  • catch potential and processing capacity
  • catch-to-shore processing
  • deck space and catch areas
  • sea surface activity spotting
  • crew management and safety
  • line of sight through working and observation areas
  • communications between decks
  • helmsman observation
  • crew accommodation and working areas
  • handling at sea, working and underway
  • fuel consumption and passage time

STUDY PLANS - by post $USD100.00 | FULL BUILD PLANS - available on application

KANSAI is currently developing plasma-cutting plans which will provide kitset instructions & plans for ship builders & fabricators.
  • 01 plan overview
  • 02 plan profile
  • 03 plan bowprofile
  • 04-plan top
  • 05-plans-drawings
  • 06 plans 3d hull
  • 07-3d-plans-superstructure
  • 08 plans-mid-cross-section
  • 09 plans cross section at superstructre
  • 10 plans through superstructure
  • plan overview larger 02

What makes this boat so REMARKABLE?

  • ENGINE INSTALLATION - twin or single engine configuration.engine-02

    Rodney recommends DONG FENG Marine diesels for the sail assisted K class in fishing vessel mode. engine-01

    The twin 4135 for main propulsion in particular or the 6135 model for a single engine installation.

    The same marine diesel engines can be used for fishroom refrigeration gensets and or with a smaller model for running ships power separate to this. 
    This gives simplicity and uniformity with all interchangeable parts between engines and reducing spare parts needed to be carried including filters etc. 
  • Crew are under cover from rain and sun while working the aft catching deck.

    Choose from 144 or 180 cubic metres.
    Refrigeration to -15 degrees or less.
  • Crew accommodation is low amidships, maximum 6 berths.

    A crew of 4 is plenty for this vessel.
  • The main wheelhouse incorporates a high spotting tower for easy sea surface observation.

    Sea surface activity and fish spotting from the high upper helm station is a huge bonus and with good communication between the catching deck, clear lure observation from the helmsman as the lines load up, is what is required to fill that fish room very efficiently for another profitable trip for the least number of days at sea.
  • The mast is flanged and hinged approx. 2m above the observation tower. This is easily lowered to the foredeck for maintenance.

    Rigging is kept clear of the decks so there is no deck clutter.

    Easily handled, roller furling/hanked headsails can be operated by someone with minimum sailing experience.
  • Sail-assisted trolling reduces fuel costs, increases stealth and also makes for a more enjoyable working environment.

    The simple, easy to operate sail rig allows for stealthy, almost silent trolling and is designed to keep the decks clear.

The NINNA MARIANA en route from Albany, Australia to Tauranga, New Zealand.

ninna-mariana-01  ninna-mariana-02 

It was this epic journey that inspired Rodney Davidson to develop his concept for a sail-assisted tuna boat. After many years of consulting, designing and testing, KANSAI is now proud to offer this innovative design to fleet operators and individuals around the globe.