China's young and handsome sailors and marines in the National Day parade Thursday impressed the audience on Tian'anmen Square and nationwide with the country's growing ability to guard its coast and territorial waters.

Formations of cadets, sailors and marines represent the progress the country has made in building a multi-dimensional naval defense capable of diversified missions.

"Under a transition from inshore protection to offshore defense, the Navy has made notable changes to become a real blue-water force and match its capabilities to the country' s international status," Zhang Shiping, deputy dean of the war theory and strategy research department under the Chinese Academy of Military Sciences, told Xinhua.

Cadets in the first naval formation in the parade were from the Dalian Naval Surface Warship Academy. Founded in November 1949, the academy is regarded as the cradle of the country's warship officers.

About 40,000 officers have graduated from the academy over the past 60 years, among whom 180 have become admirals and 1,200 become captains of warships.

Now the Navy has four academies, training 5,000 sailors, marines and officers annually. Every year, it also recruits about 1,000 college graduates from prestigious civilian universities.

Founded in 1927, the People's Liberation Army (PLA) did not have a navy until April 1949. The fleet mainly grew out of Kuomintang warships which surrendered or were seized by the PLA during the civil war.

Today, the Navy has expanded to a force of warships, submarines, naval planes, coast defense force and marine corps.

"The strategy of naval defense has changed with China's reality and national interests," Zhang said.

In the first three decades since 1949, the navy focused on guarding the coast as New China was struggling to keep its territory safe and stable, he said.

After the reform and opening up drive started in 1978, the country created a better international environment and realized a fast economic growth, which allowed the Navy to improve its capacity and expand its reach, he said.

As submarines, missiles and depot ships began serving, submarine crews have appeared on the National Day parade since 1984. This year, the formation of sailors, all from the Navy Submarine Academy, was the youngest with the members aged 18 on average.

When the PLA Navy established a submarine unit in 1954, the only two submarines it had were given by the Soviet Union.

Today the country's submarine fleet is made up of home-made conventionally-powered and nuclear submarines with the combat capabilities greatly improved.

In a landmark offshore fleet review in April to mark the PLA Navy's 60th anniversary, two homebred nuclear submarines, the Long March 6 and the Long March 3, made their maiden show. It was the first public appearance of China's nuclear submarines, which first served in the Navy in 1974.

"Over the past six decades, the Navy has finished weapons upgrade from semi-mechanized to mechanized. Now we are incorporating computer and information technologies," said Wu Shengli, the PLA Navy commander, in an interview with Xinhua.

The marine corps, in the third naval formation in the parade, is one of the youngest services in the Navy. Founded in 1979, the crops made its debut in the National Day parade in 1999, signaling the Navy's breakthrough in land warfare.

"With expanding national interests and increasing non-conventional security threats, the Navy has carried out more and more peacetime missions," Wu said. Maritime rescue and anti-terrorist capacity have been included in the capacity building.

Last May, the marine corps conducted the second large-scale disaster rescue task after the 1998 flood along the Yangtze River -- 2,750 marines were sent to the southwestern inland province of Sichuan to carry out rescue work in the deadly 8-magnitude earthquake. This was also the first time they had traveled such a long distance of 1,800 km in just two days.

"It was after the year 2000 that the Navy fully established its blue water strategy," Zhang said.

The Navy is improving its capacity in deep-sea and long-distance missions, Wu said. "The Navy has adopted regular long-distance exercises."

Last December, the Navy sent a flotilla to the Gulf of Aden and Somali waters as the country's first deep-sea escort mission. So far three flotillas have been rotated and 555 civilian ships have received their protection.

The country' s growing ocean presence is part of its peaceful development and represents its interests on a planet three-quarters covered by water.

"Being a responsible nation, China also bears the task of maintaining world peace. Without an effective navy, the task will not be fulfilled," Zhang said.

But both the Navy and experts stressed its defensive nature.

"China's national defense policy and nuclear strategy are purely defensive in nature, and the country's naval forces will not pose any threat to other countries," said Ding Yiping, deputy commander of the PLA Navy, in an interview with Xinhua in April.

Issued in January, the white paper on China's National Defense in 2008 said China implements a military strategy of "active defense" and it will attack only after being attacked.