This is one man's story which will overwhelm the reader with the originality of what a man can do with his life. Robert Marx, 30, first ran away from home at 9. At 13 he left for good, took up dive-by-night salvage in Connecticut, went to California to skin-dive. But treasure research really fascinated him and he filled 11 footlockers with notes. Korea came and he enlisted with his footlockers in the Marines. Off-shore South Carolina, he located The Monitor and became world-famous. Discharged, he teamed up with Clay Blair, Jr., and began to treasure-dive in earnest. Dizzying developments took Marx to Madrid where he next joined up with Carlos Etayo who was building an exact replica of Columbus' diminutive ship Nina, planning to sail it to America. Marx, arlos and seven others set out on the crossing with no modern equipment, expecting to duplicate Columbus' voyage in every possible respect. But... 17 days out from the Canary Islands, the Nina II was 700 miles farther from America than when leaving the islands. For she was so plagued and unseaworthy that she made the longest Atlantic crossing in navigation's history- 77 days. Columbus did it handily in 36. A German had done it better in a kayak. However, while jinxes settled like barnacles on the Nina II, none have attached themselves here in this admirably vigorous account.