THE reader wanting to invest time and money in one good biography of Christopher Columbus to mark the 500th anniversary of his arrival in the New World will find Samuel Eliot Morison's 1941 book, Admiral of the Ocean Sea: A Life of Christopher Columbus, now reissued by Little, Brown & Company (680 pp., $29.95 cloth, $24.95 paper), hard to beat.To this big, satisfying doorstopper of a book John Noble Wilford's The Mysterious History of Columbus: An Exploration of the Man, the Myth, the Legacy (Alfred A. Knopf, 318 pp., $24) makes an interesting counterpoint, if not quite a counterweight, Wilford's being much the slenderer volume. He presents not so much a biography per se - to the extent he does, he draws heavily on Morison - but rather an overview of the story of the story of Columbus. He considers the great discoverer's place in history and i n the United States, a nation whose shores Columbus never quite reached but whose collective imagination he has captured. Morison was not only a historian but a sailor, and his life of Columbus focuses on the fundamentals: the Genoese discoverer as a sailor and navigator. Morison cites the model of Francis Parkman, "the greatest North American historian, [who] was not content to study the documentary history of Canada in his Boston library. He followed the routes of the French explorers, camped in the primeval forest, and lived among primitive Indians." As a result, he says, Parkman's history is "no mere flat land made of words out of other words on paper, but a fresh creation in three dimensions, a story in which the reader is conscious of space and light, of the earth u nderfoot, the sky overhead, and God in His Heaven." Morison's version of the Parkman approach involved going to sea himself, in vessels approximating those of Columbus's fleet, and following his courses - to the extent they can be reconstructed from the records. That extent is limited; Morison, unlike most biographers, presents no general chart of the Four Voyages, as he rather grandly capitalizes them. But there are no authentic materials for tracing the ocean crossings, except for those of the First and the outward passage of the Third. Likewise, he presents no "authentic portrait" of Columbus - none exists - and concedes that any pictures one sees of the Nina, the Pinta, and the Santa Maria are all "about 50 percent fancy." And yet one is somehow surprised at how little debunking there is in the biography. In fourteen hundred and ninety-two, Columbus really did sail the ocean blue. He didn't have to convince the kings and courtiers whose support he sought that the world was round; they knew it, and so did the simple sailors who could see ships "hulling down" as they drifted over the horizon. Where Columbus was wrong and the naysayers of the courts were right was on the circumference of the earth: He seriously underestimated it; yes, there is a theoretical westward passage to Asia from Europe, but Columbus didn't allow enough distance for it. If the Americas hadn't been there for him when his crews trembled on the brink of mutiny, nobody would be preparing for a Columbus Day parade this weekend. But chance favors the brave, Morison observes. His eminently readable book, through which one cuts as smoothly as Columbus sailed west to the Bahamas on his First Voyage, depicts Columbus as a superb mariner of the 15th century. He relied on dead reckoning rather than celestial navigation, but he had a vision to be realized. He intuited what he could not have known. At a critical moment, he followed a hunch from the flight of some birds instead of what his navigational evidence told him - and he made lan dfall. A modern temptation has been to make more of Columbus as a man of scientific discovery in a way that the facts don't quite justify. The great European scientific revolution lay far in the future as Columbus and his crews set forth in their little ships. Both Morison and Wilford - each a Pulitzer Prize winner, by the way - give us a Columbus with one foot in the medieval era and one in the modern. Wilford in particular stresses Columbus's religiosity, his sense of his role as "bearer of the Christ," as suggested by his own given name. Columbus's "Book of Prophecies," prepared after his Third Voyage, is described as a notebook or handbook of sources, statements, opinions and prophecies on the subject of the recovery of God's Holy City and Mount Zion, and on the discovery and evangelization of the islands of the Indies and of all other peoples and nations. It was the work of a man who believed himse lf an agent of a divine plan - a concept problematic for many modern historians. Modern historians have less trouble considering the devastating effects of the arrival of the explorers on the indigenous peoples of the New World, and neither of these two books avoids the issue. The story of the Spaniards' harsh treatment of the natives has been known as the "Black Legend," but Wilford gives the Spanish credit for eventually realizing the enormity of their behavior and trying to do better. Since he never reached the mainland of the United States, and the dominant culture of the US grew out of the English rather than the Spanish colonies, it is striking how Columbus has become a specifically United States hero. Wilford has an interesting section on this. Over the centuries Columbus became transmogrified into a symbolic - if not actual - discoverer of America as New World, as Promised Land, as Eden before the fall. Later Columbus was a legitimating hero. Irish Catholic immigrants organized t he Knights of Columbus in New Haven, Conn., in 1882, "in a response to adverse Protestant attitudes and to affirm their own Americanism," Wilford says. It may be true, as commentator Garry Wills has written, that Columbus has been "mugged" on the way to his own quincentennial, but it would be a shame to lose the man in the controversy. These two volumes should help keep that from happening.