Nearing graduation, his class was exposed to the various components of the Russian fleet. Ramius at once fell in love with submarines. The boats at that time were small, dirty, and smelled from the open bilges that the crews used as a convenient latrine. At the same time submarines were the only offensive arm that the navy had, and from the first Marko wanted to be on the cutting edge. He'd had enough lectures on naval history to know that submarines had twice nearly strangled England 's maritime empire and had successfully emasculated the economy of Japan . This had greatly pleased him; he was glad the Americans had crushed the Japanese navy that had so nearly killed his mentor.

He graduated from the Nakhimov School first in his class, winner of the gold-plated sextant for his mastery of theoretical navigation. As leader of his class, Marko was allowed the school of his choice. He selected the Higher Naval School for Underwater Navigation, named for Lenin's Komsomol, VVMUPP, still the principal submarine school of the Soviet Union.

His five years at VVMUPP were the most demanding of his life, the more so since he was determined not to succeed but to excel. He was first in his class in every subject, in every year. His essay on the political significance of Soviet naval power was forwarded to Sergey Georgiyevich Gorshkov, then commander in chief of the Baltic Fleet and clearly the coming man in the Soviet Navy. Gorshkov had seen the essay published in Morskoi Sbornik (Naval Collections), the leading Soviet naval journal. It was a model of progressive Party thought, quoting Lenin six different times.

By this time Marko's father was a candidate member of the Presidium, as the Politburo was then called, and very proud of his son. The elder Ramius was no one's fool. He finally recognized that the Red Fleet was a growing flower and that his son would someday have a position of importance in it. His influence moved his son's career rapidly along.

By thirty, Marko had his first command and a new wife. Natalia Bogdanova was the daughter of another Presidium member whose diplomatic duties had taken him and his family all over the world. Natalia had never been a healthy girl. They had no children, their three attempts each ending in miscarriage, the last of which had nearly killed her. She was a pretty, delicate woman, sophisticated by Russian standards, who polished her husband's passable English with American and British books—politically approved ones to be sure, mainly the thoughts of Western leftists, but also a smattering of genuine literature, including Hemingway, Twain, and Upton Sinclair. Along with his naval career, Natalia had been the center of his life. Their marriage, punctuated by prolonged absences and joyous returns, made their love even more precious than it might have been.

When construction began on the first class of Soviet nuclear-powered submarines, Marko found himself in the yards learning how the steel sharks were designed and built. He was soon known as a very hard man to please as a junior quality control inspector. His own life, he was aware, would ride on the workmanship of these often drunk welders and fitters. He became an expert in nuclear engineering, spent two years as a starpom, and then received his first nuclear command. She was a November-class attack submarine, the first crude attempt by the Soviets to make a battle worthy long-range attack boat to threaten Western navies and lines of communication. Not a month later a sister ship suffered a major reactor casualty off the Norwegian coast, and Marko was first to arrive on the scene. As ordered, he successfully rescued the crew, then sank the disabled sub lest Western navies learn her secrets. Both tasks he performed expertly and well, a noteworthy tour de force for a young commander. Good performance was something he had always felt it was important to reward in his subordinates, and the fleet commander at that time felt the same way. Marko soon moved on to a new Charlie I-class sub.