The Waka Tapu journey from Aotearoa to Rapanui (Easter Island) and back, which closed the Polynesian triangle, was navigated without instruments.

The three main techniques that navigator Jack Thatcher used on the journey were:

  • understanding and using the star compass
  • dead reckoning
  • knowing where your destination is all the time.

The star compass is the most important and vital knowledge for wayfinding. It is a representation of the whole environment. It includes the stars, Sun, Moon and ‘houses’ on the horizon between the sea and sky (the ‘houses’ are dictated by the rising and setting of heavenly bodies). Knowing the star compass is to understand your environment, and then you work out where your canoe (the only instrument) fits into that environment.

Dead reckoning is to calculate where you are at a given moment in time and where you are going to be later, based on the performance of the waka. You need to keep a mental track of that 24/7.

The third main technique is to be clear about your destination at all times, so if you deviate from the course for whatever reason (for example, winds or a storm), you are constantly aware of where you should be and return to your course as soon as possible.

Establishing direction – the course line

To know your position within the environment, Jack describes establishing a direction or course line from one point to the next. This line is worked out using the Sun, Moon and stars (the star compass) and becomes a reference point for all calculations. Everything is based on that line. Knowing where that line is all the time is a part of knowing where the destination island will be, because the line terminates at that island. You will also know where you are in relation to the island as you move towards it. Once the course line has been determined, you need to maintain that direction.

Calculating distance

Distance can be worked out mathematically using western ideas about speed (miles or kilometres covered per hour) or by using a more ancient way. The old way is based on the knowledge of the time taken to get from one particular island to another (for example, half a day). This becomes the standard measurement for distance that is used to estimate the distance to the next island. You measure the time it takes and compare it to the first measurement, for example, it might be the same as the first time (half a day – so a similar distance) or it might take 20 times as long to get there (10 days). This gives you an idea about distances between islands.

Measuring speed

An indication of speed can be obtained by counting how long it takes whitewash (a splash) to travel from the bow to a certain point at the stern. This gives a basic indication of the canoe speed and can be used to calculate the time of travel. Mathematical principles can be used to calculate speed, distance and time. You use the values you know to work out the unknown ones.

  • Speed = distance/time
  • Distance = speed x time
  • Time = distance/speed

Refining techniques

Jack used this journey to refine some navigating techniques. He devised a way to maintain direction at difficult times of the day such as when the Sun is high in the sky. Maintaining direction is based on the point at which the Sun rises from the horizon. It rises to the east, but its specific rising point depends on the season and your position on the globe. However, once the Sun gets too high, it’s hard to trace it back to its rising place on the horizon.

Jack’s technique involves finding north based on observations of the Sun after midday. Jack says it’s not very accurate, but it does confirm whether or not you are going in a constant direction. He also worked out a way to teach this to his students.

Equipment for safety only

Modern equipment on board the waka was used for safety only, not navigation. A satellite phone was used to send back waka positions so that others could track the Waka Tapu. VHS radios were used for interwaka communication. This was necessary when a problem arose, such as paddles breaking or when waka became separated. The lead waka (Te Aurere) did all the traditional navigating with the support waka (Ngahiraka Mai Tawhiti) following.

Useful links

The official Waka Tapu site that tracked the voyage to Rapanui and back.
www.wakatapu.com

Waka tracker – satellite points showing the path of each waka (Te Aurere in green and Ngahiraka Mai Tawhiti in red. The white track was the predicted path to Rapanui and back.
http://teaurere.smartbitz.co.nz/Voyages/ViewTrack/1AAukqlLpHhOYXA2F31T?showmenu=false

    Published 13 November 2014