Seven-Tenths Read Online Free Page A

ever. Even the crew seems less laconic while all this is going on. When we are under way again there is a feeling that the Farnella is more in the hands of scientists than seamen and the crew can now be found in odd corners reading copies of the Hull Daily Mail which were flown out in bundles to the shipping agent in Honolulu. Shipboard life settles into routine. It is still curious to be in the Pacific in a British ex-trawler with a television in the lounge showing video-cassettes of highlights from last season’s Hull Kingston Rovers matches. Not to mention the cuisine. At the same time we are, as an IOS zealot proudly says, ‘at the leading edge of geophysical seabed surveying’.
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    The issue of who is really in command of the ship is interesting, as is the whole idea of a joint survey paid for by the US Government using a significant proportion of British equipment and scientists. In a legal sense the Captain has full and final responsibility for the ship. Yet it soon becomes plain that his actions are largely determined by the exigencies of the survey, which is costing the American taxpayer such a pretty penny. It is the USGS which has chartered the vessel and hired GLORIA and so calls the tune. On the other hand the scientist formally in charge of this particular cruise is a Briton, one of GLORIA’s original developers at IOS. At the same time one of the young American women aboard is responsible to her government for completing this leg of the survey. … All this interweaving of authority is glossed for me as ‘A joint effort. Absolute cooperation and consultation. Democracy in action like you wouldn’t believe.’ This is emphatically not science for the sake of science, a matter of drifting about the Pacific like the old Challenger in the 1870s, sounding here and dredging there at whim. This is time-and-motion science, with a given area of blank map to be filled in a given time. And the whole issue, for very cogent reasons of physics, hinges around the matter of navigation.
    As is all too clear to anybody swimming in circles looking for a lost boat in the middle of the ocean, one has no position in water. When mapping the seabed from a moving ship, therefore, accurate navigation is of crucial importance. Without the ship’s positionbeing known from one second to the next the most beautiful chart of peaks, ravines and plateaus would be useless. The only thing known would be that they were down there somewhere. Establishing the ship’s course along lines as straight as possible (always allowing for the Earth’s curvature) requires much work, not least because the swathes GLORIA maps must lie next to each other without gaps or wasteful overlapping. On the chart table in the lab is the dot of Johnston Island, a pencil circle whose diameter represents 400 nautical miles inscribed about it. High up in its top left-hand quarter a chord shows the first leg we have just started. Next to it is written the estimated time at which we should come about for the return pass, each leg getting longer as we eat downwards into the circle. If all goes well, by the end of a fortnight we should have hatched off about a quarter of the total area.
    While the lab computers flicker with the instruments’ returning signals, various repeater gauges give the ship’s speed through the water, its speed over the ground, the wind speed and any consequent degree of yaw. If to remain on a straight course against a quartering wind and current the Farnella needs to sail crabwise, GLORIA’s angle will also be fractionally oblique to its correct path. The result is that its signals will no longer be exactly at right angles to this course and the map will be distorted. Information on all these factors is fed into the computers, which correct for them. In order to determine the ship’s position at any moment the Farnella uses GPS or Global Positioning System. This depends on satellites and eventually, provided there are still spare slots in an