Eastwind (WAGB 279) - Naval Cruise Book

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While enroute northward along longitude 78 east, part of the oceanographic team ran tests on the samples while others, under the d1rect1on of Navy Chlef Raymond J Davis of Thomas ville North Carolina, took hourly BT s short for bathyothermograph readlngs A torpedo shaped lnstrument about three feet long was unreeled from a small wire wlnch and allowed to seek great depths be hind the ship When brought up, a needle had made a continuous recording on a smoked glass slide of water temperatures at all depths This was an excellent method of determin- ing the thermocline says Chief Davis. The thermocline, he explains, is a layer of rapiollylclecreasing temperature usually about 150 feet below the surface. The primary importance of recording ex- actly where the thermocline begins in various areas, is the fact that submarines can cruise undetected below this temperature blanket. Perhaps the most interesting time aboard the Eastwind occurred when the icebreaker reached a station destination during the even- ing hours. A huge floodlight illuminated the water's emerald surface in a large circular pat- tern. Crew members gathered around to watch Officers and men takerefreshmg dip rn Indian Ocean Cigar smokmg bosun smate hammers old paint from hull of ship

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., V . . ,. . J vu it i, A . -...mu-..4...-r-.... . an Dr. Tressler and his team of five Coast- Guardsmen and a Navy Chief Quartermaster literally worked around the clock gathering data on salt content, amount of oxygen, marine life, and ocean temperatures at different underwater levels. They also recorded ocean depths, of which very little was known in the Indian Ocean. The most up-to-date charts of the area indicated soundings as much as 700 miles apart in some cases. One day, as the Eastwind approached a pre- determined station, her fathometer jumped rapidly from 15,000 feet to a mere 2,850 feet. Like an explorer who has set foot on virgin territory, Dr. Tressler still quivers with excite- ment at the recollection. Imagine, he says, art underwater moun- tain ofver 12,000 feet high that no one had probably efver dreamed existed before. Since a deepwater survey was required on the spot, the ship had to move a few miles further down her trackline, where the sounding soon returned to 15,000 feet. Standing on specially constructed platform bottleman stands by to unhook Nansen bot- tle iust reeled from the deep. When Eastwind arrived on station, her engines were cut and she wallowed like a lazy whale in the trough of the sea. During daylight stations, the searing tropical sun heated the cork insulated icebreaker to dizzying heights. A small platform about three feet square was locked into position over the side and a member of the oceano- 3 graphic team got set to make a cast. Wire was unreeled over the side from a huge electri- cally powered drum and atintervals steel Nansen bottles, open at both ends and with thermometers attached, were hooked on. When a total of 12 bottles had been secured to the wire like beads on a string, they were lowered to pre- determined depths with the bottom one nearly two miles below the surface. A weight was then sent down the wire, setting off a chain reaction which closed each bottle, sealing inside a sample of the water at that depth. Then the bottles were reeled to the surface, unhooked, their temperatures recorded and contents analyzed. An average cast took about three hours. Then the ship would get underway for the next station, sometimes 120 miles away, sometimes 60. lcontinuedj Bottleman attaches steel water sample collector to wire. 2 X A

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r Diver plunges toward cool wafer as other crewmembers scramble up lines. Crewman on scaffolds clean ship asicebreaker cuts swath through flat calm sea. operations and fish for sharks and squid. Oc- casionally, a huge shark would make a pass at one of the bright yellow Nansen bottles near the surface, just a few feet under the seaman who was attaching other bottles. To guard against mishaps, the Bottleman wore a safety harness. ' It may be my imagination, smiled Dr. Tressler one evening on station as he pointed to a big shark circling around the bottles, but that fellow ofver there has been following as since we dumped garbage off the west coast of Australia. Almost as though offended at being singled out, the large shark turned over, and showing the white of its belly, dived for the deep. Dr. Tressler received his doctorate in Limnology Qsometimes called fresh water oceanographyj from the University of Wiscon- sin. Limnologists do most of their studies from rowboats, in rivers and lakes. Tressler admits that doing tropical oceano- graphy from an icebreaker is a far cry from his rowboat days. But, he explains, It's basically the same type of work, discovering more about the physical, chemical, and biological worldaround us. When the Ocean Survey swings into high gear next year, 15 nations will set up sea and shore stations ringing the Indian Ocean. Until then, the Coast Guard Icebreaker Eastwind, has had the distinction of getting the project off to what might be called in ice- breaking circles at least, a 'cool start.