With the Canadian Hydrographic Service aboard the MV Theron — 1954-55
Our primary objective was to reach Hudson Strait from where we could head west to Rankin Inlet on the northwest coast of Hudson Bay which was to be the area of our main charting operations that season. But our immediate intention was to reach the icebound Hopedale area, halfway up the Labrador coast, where we would carry out offshore charting in the interim while waiting for the ice conditions to improve and allow us to make our northing.
When we were on passage we stopped our ship at intervals, day and night, to make oceanographic observations of the temperatures at various depths and to take samples of the seawater at those depths. Apart from gaining general scientific knowledge for studying fish populations and other subjects, such information, with the cold war then at its chilliest, was often secret and important for antisubmarine warfare purposes; it being thought that submarines might more easily navigate underwater if they had seasonal charts of expected temperatures and salinity gradients.
These observations were made by lowering a string of reversing water bottles down into the depths. The bottles were made of heavy metal and each one had a special thermometer attached. Also they had spring-loaded snap lids at each end which could be activated to shut closed when triggered. So if for example the ship was stopped in 1000 feet of water, the end of the wire which was lowered into the water by winch, would first of all have a bathythermograph attached to the end. This instrument worked a stylus that drew a line on a small piece of smoked glass about one-and-a half-inches square. It actually inscribed a miniature graph of the temperature gradient from surface to the lowest depth it reached. Just above this gadget the first, or in fact what would become the last or deepest, water bottle would be attached with its end lids open. The wire would then be lowered 100 feet, or whatever interval had been decided upon, and the next water bottle would be attached to the wire. Hanging to the bottom of this bottle’s end cap we would attach a brass weight called a messenger. This messenger closed securely but loosely around the wire so it could slide freely down the wire and was attached by a ring to the bottle’s lower lid mechanism in such a way that when the bottle was activated from above the messenger underneath would be released and fall down the wire to hit the next bottle below and activate it in turn.
The wire would now be lowered another hundred feet and another bottle with another messenger attached to the wire. Eventually, a string of water bottles, all in an upright position and at regular intervals would reach from the surface of the ocean down to just above the sea floor. When all was ready the hydrographer would attach a starter messenger to the wire and give it a push down the wire to activate the first water bottle which would be just under the surface of the water. By keeping an ungloved hand-hold around the wire one could at once feel the shock and vibration as the messenger hit the top of the water bottle, triggering both of its ends to snap shut. In turn that bottle's messenger was released, and the water bottle fell into an upside-down position trapping a sample of the water at that depth and locking the mercury in its thermometer to record an exact reading. Within a few more seconds one would feel another tremor and vibration as the second water bottle was activated. Then, hoping the next bottle’s messenger had been released, an inordinate amount of time would seem to pass before another, but fainter vibration of the wire was detected. As the lower bottles in the denser layers of ocean were activated, at much longer intervals of time, the vibrations felt on the wire would become fainter and fainter. The messengers, each released in turn from the distant bottles far down in the dark depths, seemed to take an eternity to slide down the wire and reach the next bottle. Until with only one to go, the last, most important one, and still with a cold bare hand wrapped expectantly around the taught wet wire one would become convinced that the last messenger had not been released as it should have been. And convinced that the long, long minutes spent leaning over the wallowing ship’s heaving side in the midnight darkness with an icy wind blowing, peering at the wire where it disappeared into the dark water below was just a waste of time. One might as well forget thoughts of the nice warm bunk awaiting in the snug cabin and admit failure as regards the last bottle. We would have to bring all the wire back up and reset that one cursed bottle and repeat the lengthy task. And then just as all hope had drained away and a signal to the seaman at the electric winch was about to be reluctantly given, the faintest of telltale tremors, no more pronounced that a hummingbird’s passing, an autumn leaf’s touching on the forest floor, a snowflake’s landing, one would feel, amid the turmoil of the heaving water and the odd piece of sea-ice bumping against the ship’s steel hull, the sightest, welcome, tremor.
Then one could happily give the signal to hoist up the string and as the winch whined away and each water bottle arrived at breast height it could be released from the wire, its seawater sample poured into a numbered jar and its thermometer reading recorded. Then the next bottle, and the next and the next, until all were safely aboard and stowed away and one could go back to bed for a couple of hours until the whole business would be repeated in another part of the ocean.