THE DESIGN

The following parameters are considered imperative in the design of Whio:

• The overall dimensions have to be below those which would incur the necessity of an oversize permit for trailering.
• In the interest of fuel economy and trailering Whio has to be light and wherever practible the lightest materials possible must be used used.
• Whio has to be capable of making coastal passages safely and at speed and be able to cope comfortably with adverse sea conditions.
• Taking all the above into account, Whio has to have the appearance and elegance of a classic Edwardian launch.

BUILDING

Whio is built on a mould using kaihikatea stringers. Laminated cedar and macrocarpa frames are inserted after removal of the the moulds. She is planked with cold moulded diagonal kauri, with two skins above the chine and three below. She is fastened with bronze screws and plastic nails. The whole hull and plywood decks are sheathed with 300g glass cloth. The cabin top is built of plywood and, to keep the weigh t down, cedar is used for woodwork such as the wheelhouse pillars and framing. For appearance kauri is used for trims. Cedar is also used in the structure of interior cabinetry, which is totally removeable for access and maintenance. The floorboards are laminated using cedar with a foam core, saving about 80kg in weight. Engine bearers are substantially extended to strengthen the keel, particularly for loading onto the trailer.

ENGINE

Whio's engine is an 1800cc Toyota diesel (2004), marinized with a heat exchanger, raw water pump, fuel cooler, intake silencer and water-cooled exhaust. The ZF gearbox has a 2.74 to 1 reduction.

PROP

The propeller diameter is large (21.5 X 21.5 ins.) to enable slow revving which results in a much higher efficiency than smaller high revving props. The propeller had to be specially constructed to mount on four studs for easy and quick removal when on the trailer. To further assist the efficiency of the prop careful attention was paid to the fairing of the deadwood and skeg (which is removable for trailering).

STEERING

To save space and weight a side staff is installed with 6mm Spectra cables passing through ball bearing sheaves to the tiller.

AMENITIES

• Built in fridge and freezer
• Berths for 2/3
• Economical LED lamps
• Depth sounder
• Portable gas stove.
• At present a Portable loo is provided, but is intended to install a drying type head.
• Awnings are provided to enclose the after part of the boat.

ANCHOR

PERFORMANCE

Fuel consumption : aproximately 2 litres per hour at 10 knots. Accurate measurements have not been made for higher speeds but is estimated that it should not be greater that 6 to 7 litres per hour at 17 knots.

In easy sea conditions she cruises comfortably at 15 knots and 12 in heavier conditions, Whio rides smoothly with very little pounding. She steers very well running before the sea with no tendency to broach.

THE DESIGNERS

The design of Whio was the resolution of ideas, which Peter Sewell and Bill Simpson had long held, that there is a place for combining the best of traditional launch design with modern materials, techniques and power sources. Bill's imput was in the refinement of aspects of the hull shape and Bill and Peter together worked up the design of the hull.  Peter then built a half model from which Whio was built. The building of Whio, the engineering of the propulsion plant, the cabinet work of the interior and finishing were almost entirely Peter's work although he thanks the many friends who gave him encouragement and helped with either donkey work or special details.

  Whio was Best Overall boat and winner of the Jens Hansen Cup for 2006 at the
  Seresin Estate Antique and Classic Boat Show held at Lake Rotoiti in the Nelson Lakes National Park 
    

Whio was also featured in issue 190 of WoodenBoat magazine.