Streamlining old boat designs

Shipping

A CONSULTANT boatbuilder working for the United Nations regional fisheries programme recently completed building and testing new types of boats in Rarotonga.

In French Polynesia and the Cook Islands small speedboats are used to

catch flyingfish.

These boats, called poti marara , evolved from pleasurecraft which were intro duced to Tahiti in the 19505. Some people believe that the potio marara as well as the larger skipjack boats known as bonitier were first introduced by the American sportswriter Zane Grey on his gamefishing trips to Polynesia.

The design of the vessel has evolved considerably since those days. In French Polynesia a few four-metre boats pow ered by an outboard engine of less than 10 horsepower in the 1950 s became a fleet of nearly 300 50-metre craft which

use engines averaging a whooping 75hp.

In Rarotonga a similar evolution took place, but the typical engine of today, 40hp, is a bit more modest.

In mid-1990 the Ministry of Marine Resources in the Cook Islands felt that there was considerable room for improv ing the poti marara: the size of outboard

was getting somewhat ridiculous, the hull design was thought to be less than optimum, and the construction tech niques used by the mainly amateur builders of this design frequently were not the greatest.

To obtain a better poti marara , the Ministry asked the United Nations fisheries programme to provide a naval

Outboard sizes were getting ridiculous, hull designs weren’t optimum

architect to improve the design and for a boatbuilder to demonstrate proper

construction techniques.

Consultant boatbuilder Mike Savins and naval architect Oyvind Gulbrandsen worked together on the project. Savins has instructed in boatbuilding in most Pacific Island countries, while Gulbrandsen has de signed most small commercial craft now in use in the Pacific Islands, including the Fiji 28ft inboard, the Western Samoa catamaran, the 8.8 metre Tonga vessel,

and the plywood sailing/fishing canoe in Kiribati as well as other designs in Vanuatu, Solomons and PNG.

After studying details of the fishery in Rarotonga and existing craft, Gulbrandsen produced plans for two types of improved poti marara. These boats, called CKI-1 and CKI-2, were then constructed by Savins in

Rarotonga.

To enhance general boatbuilding skills and to teach specific procedures for building the new designs, Savins con structed the two boats with trainees from several areas in the Cook Islands and one from the Solomons.

The CKI-1 is a 4.7-metre boat de signed to use a 25hp engine. The design is a considerable improvement over local craft in the construction system, bow

section and performance, particularly

fuel economy. At 13 knots it is estimated that the new craft is 18 per cent more fuel efficient.

The CKI-2 is more of an experimental craft. It is a 4.7-metre trimaran, with a relatively narrow hull for speed and two

small outriggers for stability. Although it

shows considerable promise for flyingfish fishing, a larger version may be suitable for tuna fishing.

The designs for both include emer gency sail rigs for use if the outboard

engine develops problems. □