Groton — First lady Michelle Obama gave the crew of the USS Illinois (SSN 786) the traditional order to "Man our ship and bring her to life" at the commissioning ceremony Saturday for the Virginia-class vessel touted by Navy officials as the most modern and sophisticated attack submarine in the world.

Mrs. Obama, who grew up on the south side of Chicago and who has taken great interest in the well-being of military families during her husband's presidency, is the sponsor of the Illinois and has her initials etched on a nameplate on its hull. She arrived at the Naval Submarine Base via motorcade about 10:30 a.m., joined the other "distinguished visitors" on stage and toured the boat for about half an hour following the ceremony.

"Working with our military community has been the biggest honor of my life," she said. "I am beyond proud. Your commander in chief is also proud."

Adm. John M. Richardson, chief of naval operations, gave the official order to commission the boat. The crew of 137, known as the "plankowners," ran onto the submarine, their medals jangling on their uniforms, before raising the masts and sounding the ship's whistle.

In his keynote speech, Richardson said he wished he could bring every American to the shipyards that build submarines "to see the amazing things that can be done when you put your mind to it."

"They built this vessel in thousands of tons down to precision that's measured in thousandths of inches," Richardson said. He joked that the boat "will never need to pull in for gas" because its core, or nuclear reactor, was built to last for the entire 30-year life of the submarine.

The Illinois, built by Electric Boat and Newport News Shipbuilding in Virginia, is the 13th Virginia-class nuclear submarine. Naval officials said the boat was delivered four days early and more than $100 million below target cost. It cost $2.7 billion.

Construction began in June 2014, and at a keel-laying ceremony at Electric Boat's Quonset Point facility, Mrs. Obama pronounced the boat "really cool." The first lady also attended the ship's christening at EB's Groton facility on Oct. 10, 2015.

The Illinois will undergo a year of sea trials, known as "post shakedown availability," after which it will go to its homeport, which has not yet been announced. Cmdr. Jessie A. Porter has served as the boat's captain through construction and commissioning and is expected to turn the boat over to a new captain, Cmdr. Neil Steinhagen, in a change-of-command ceremony on Monday.

Porter said he watched the boat go from "pallets and packing crates to the fine instrument you see today." He said taking a ship to sea for the first time is a monumental undertaking and that the Navy had been able to leverage the skills of some of the best submariners. He thanked the crew's spouses for their support.

"You are our favorite hello and our hardest goodbye," he said.

A man dressed as Abraham Lincoln attended the ceremony as a nod to the ship's namesake state. In the opening speech, Gov. Dannel P. Malloy noted that Connecticut and Illinois have another Navy connection, Gideon Welles of Glastonbury, who served as secretary of the Navy under Lincoln from 1861 to 1869.

U.S. Rep. Joe Courtney, D-2nd District, said the Illinois and the USS Washington, which will be commissioned next year, are the first boats delivered under the accelerated build rate of two attack submarines a year. He said the impact of the increased construction can be seen across the entire region.

Sen. Richard Blumenthal, D-Conn., said he was proud to be back at the submarine base for another event and told the first lady that she was "really cool." He thanked all the workers who walk through the gate at Electric Boat every day and work tirelessly at a task where there is no room for errors.

The Illinois features a redesigned bow — first implemented on the USS North Dakota — that includes a new sonar array and two larger payload tubes instead of 12 individual, vertical-launch missile tubes. It can operate in both littoral and deep ocean environments.

Virginia-class submarines displace 7,835 tons, with a hull length of 377 feet and a diameter of 34 feet. They are capable of speeds in excess of 25 knots and can dive to a depth greater than 800 feet, while carrying Mark 48 advanced capability torpedoes and Tomahawk land-attack missiles.

k.florin@theday.com