OUR CHANGING COASTLINE

Waipa Post, Volume 42, Issue 3271, 12 March 1931, Page 7

OUR CHANGING COASTLINE

Almost every severe earthquake in New Zealand tvorks substantial alterations in the level of the ocean floor, and alters the contour of the seacoast. Several of the great upheavals in the past eighty years have forced up the bed of the sea and brought to the surface new peninsulas and strange reefs. Rocks hitherto submerged at low water are now visible at high tide. Towering cliffs against which the waves once dashed incessantly are now hundreds of yards distant from the breaking surf, separated by low-lying tracts of land that appeared suddenly under subterranean pressure.

The majority of these changes have happily been confined to the mainland or to submarine obstructions close to the shore. But they constitute a very sound reason for suggesting that early attention hsould be given to a re-survey of the New Zealand coast, part of which has not been charted since Captain Cook felt his way carefully round its rugged sounds and treacherous inlets on his visit to the newly-discovered land in 1770. Master mariners who are not familiar with these shores have often complained that the nautical charts of New Zealand coastal waters are inaccurate and inadequate, miles out of reckoning upon vital points, and ignoring altogether the presence of many well-known marine dangers. One of the worst shipwrecks that have ever occurred close to New Zealand—the loss of the Elingamite in 1902— (was caused primarily by an error in the charted position of the Three Kings. The Kaipara Rock, in the, Hauraki Gulf, fortunately quite well known to shipmasters who trade their vessels regularly to these waters, was not marked on the charts many years ago when a French warship struck it, or later when the Waimiate grazed it, or ev<en when/ its namesake, the ship Kaipara, was piled up on it. To-day, despite its hidden dangers, the rock is marked on the chart, “ Reported but not examined.”

Some of the charts conflict; others frankly admit their complete inaccuracy. The Ariel Rocks, off the east coast of the North Island, are shown on two separate charts in positions approximately a mile and a half apart.. As it is impossible for both positions to be correct, the captain who took his bearings “ blind,” and allowed the usual safety margin of a mile and a half, would in all probability find his ship perched precisely upon the rocks. One nautical map which professes to cover the whole of our coastal waters makes the confession: “Soundings in fathoms. Note: The positions of the points on this chart differ both in latitude and longitude from the latest determination by the New Zealand Government.” The mariner who reads in his nautical almanac that “ the following bearings will place a ship a full mile from the breakwater in seven fathoms ” at Timaru, South Island, finds on laying out the position on his chart that these bearings will anchor his ship exactly on the breakwater. The chart is a mile and a half out, but, fortunately, on the side of safety. Until he acquires this local knowledge, however, he can rely upon neither the chart nor the almanac, and for safety’s sake he is compelled to engage the services of a coastal pilot while he is trading in New Zealand waters. ■ Waipapapa Point, on the far south coast, accommodating the Waipapapa Light, protrudes into the sea two miles ..further than the chart indicates. From Palliser Bay to Wel-

lington is practically an uncharted stretch of water, even though it lies in the direct route of all shipping approaching Wellington from the east. Along the west coast of the South Island the absence of reliable soundings is notorious.

In a country like New; Zealand, crossed as it is by several well-defined earth faults, where the mighty forces of Nature are for ever at work beneath the surface, it is disconcerting to shipmasters to know that their charts and guide books are inaccurate upon essential points and that one of these errors might at any time lead them into very serious difficulty. It would perhaps be a costly undertaking to re-map the whole of the New Zealand coast; but the palpable inadequacy of existing charts and the conflicting information they contain help to justify the claim of visiting mariners that some of the dangerous mistakes should be corrected and the job put in hand without delay.

It is not flattering to reflect that New Zealand has achieved a certain notoriety among mariners on account of its badly-charted coast. Everything should be done to dispel that impression and to remove as far as possible the hidden perils that lie off our shores. Much of the work could, no doubt, be done from the air. The •rapid development of aerial methods of survey has made it possible to cover the most erratic coastline quickly and easily, and without many of the irksome difficulties inseparable from a survey by sea.

Shipping interests consider this expenditure would be justified. Furthermore, they expect it in the interests of the trade they represent, and for the safety of the ships and the passengers they carry. The Government may demur that it cannot at present afford an expensive survey, but it should ask whether it can afford not to undertake it.—Dominion.