THE GULF STREAM: ENCOUNTERS WITH THE BLUE GOD by William H. MacLeish, Boston: Houghton Mifflin , 243 pp., $19.95
There is a river in the ocean. In the severest droughts it never fails, and in the mightiest floods it never overflows. Its banks and its bottom are of cold water, while its current is of warm. The Gulf of Mexico is its foundation and its mouth is in the Arctic Seas. It is the Gulf Stream.
-Matthew Maury, 19th-century US naval lieutenant
WILLIAM MacLEISH's ``Gulf Stream'' describes for the landlocked the most powerful ocean current on our water planet. Nicknamed by oceanographers the ``engine,'' it chugs at a near-constant six knots. The prime mover in a complex of currents whose tides wash four continents, the Gulf Stream transports tropical waters into frigid northern seas. Some 50-to-90-miles wide and many fathoms deep, the ``Stream'' is the dominant catalyst in moderating world climate.
For most people, the stream is simply ``out there,'' impenetrable, invisible. For MacLeish, the visible ocean is but a vestibule to cosmic forces. He takes us where divers frolic and submarines dive. But where the pressure is so great, the water so dark, and the temperature so cold that even the most sensitive, microchip-intelligent instruments are blind, MacLeish lets his informed imagination ``encounter'' the ``blue god.'' One encounter happened while scuba diving: ``There, on the tether, hanging where I never thought to be, I saw blue nothing. After 10 minutes I learned to focus in the infinity, and suddenly I had company ....''
MacLeish spent 10 years at the Woods Hole Oceanographic Institution on Cape Cod, Mass., where he edited the magazine Oceanus. He realized that descriptions of the stream must tack between the Scylla of a scientifically precise report and the Charybdis of an anecdotally vague yarn. A narrative about this force of nature must balance the ``certainty of numbers'' and ``the seduction of words.'' With sparse Yankee syntax and a poet's imagination, ``Gulf Stream'' strikes that balance.
The book's course expands in a widening gyre across the North Atlantic. We start where the mouth of the mud-brown Mississippi, like a leaky, rusty faucet (in the global scale of hydrodynamics), drips into the world ocean. Moving northeasterly, we steam, sail, drift, dive, or fly (sometimes gazing from a satellite) along the Florida current between Cuba and the southern tip of Florida, west of the Sargasso Sea and east of Georgia and the Carolinas, north of Hatteras and Bermuda, on up into the Grand Banks. We fly on air-patrol looking for icebergs off Newfoundland and make a transatlantic sail to Portugal in an old schooner. We even stroll in the ancient city of Galway, Ireland, amid fuchsia gardens and palm trees, thanks to the warm, moist air borne westerly by the stream.
In water, velocity creates eddies. The Gulf Stream creates continent-size ones. MacLeish creates verbal eddies also. He allows the plot to swirl back on itself and contemplate the stream's influence: on European settlement of the Americas, meteorological and environmental phenomena, the life cycles of sea creatures big and small. Throughout, MacLeish departs from the main current and reflects: on the boldness of the Great Admiral (Christopher Columbus), at a supertanker skipper who ``hitchhikes'' on the back of the stream, on the foresight of pioneering colleagues at Woods Hole.
MacLeish's imagination metamorphosizes as well. He writes of ``shouldering up the sea,'' transformed into bluefin tuna in search of prey. From the ``Straits of Florida, sweeping along the edge of the Bahama Banks,'' they ``feed here and there, taking squid or one of the mackerels, flying fish, even salps ... heading down the stream for the fattening grounds off New England and the Maritimes,'' adding 200 pounds to their 600-pound bulk in transit.
With awe and humilty, MacLeish seeks out planktonic salps and traces single-cell jellyfish that couple to become colossal translucent jelly snakes. Their biological rhythms remain as mysterious to scientists as the stream was to Columbus. He recounts the one-to-three year odyssey of glass eels from the Deerfield (a river near his home in Massachusetts) ``entrained'' for thousands of miles in stream currents. ``Those interested in eels used to proceed by imagination. What do you say about a being that disappears from your estuaries as a silver snake and returns as a glass worm?''
On one dive, some 80 feet down, he describes the stream's near mystical tug as the personal memory of a piano piece he played when a child (Debussy's ``La Cath'edrale Engloutie''). The melody mixes with and then becomes the bubbles ascending from his scuba gear: ``Those divers drifting over the abyss could be supplicants. Those bubbles, lofting, tumbling toward the surface, could be columns. The colors were holy enough. This could be a sunken cathedral. This, for me, could be the way in to the blue god.''
``A guarantor of life in air, the ocean is supremely hostile to observation by those who live in air,'' MacLeish writes. Thus, ``It probably is safe to predict that satellites and the new in situ instruments will reinforce the move away from the oceanographer as lone man and toward the oceanographer as organization man. But whatever he is, he will have to keep getting wet to get the truth about the sea.'' However cosmic the connection he may draw, wet we get with him.