Name: Cmdr Timothy Rexrode
Age: 43
Years on job: 20

How do you drive a 7 800-ton nuclear-powered submarine that’s longer than a football field and capable of launching 16 Tomahawk cruise missiles? Very carefully, says commanding officer Timothy Rexrode, who served his first sea tour 20 years ago on a sub designed in the 1950s. Today, Rexrode is the captain of one of the most advanced ships in the US Navy, the USS Missouri (SSN-780). The differences are striking. “We used to use paper, pencils and rulers,” for navigation, Rexrode says. “Now we’re all digital.” These days, the captain can monitor the ship with the click of a mouse and watch a live view from the photonics mast on a screen in his stateroom. But when he’s piloting the sub into port in dense fog, Rexrode still relies on his two decades of experience – not just technology – to guide him. “Half of it is instinct,” he says. “It’s pretty exhilarating.”
By Emily Haile

Anatomy of a modern submarine

Photonics masts
The traditional optical periscopes with prisms have been replaced by two masts outfitted with hi-def cameras, infrared sensors and a laser rangefinder, all controlled by joystick. Hi-res digital images can be taken from as far as a 1,5 kilometres away; they’re routed to two flat-panel screens in the command centre (shown at left), which has an open layout that puts sonar and combat systems in one fully networked room.

Sonar
The Missouri is blanketed in sonar sensors, including an array on its chin that is capable of mapping the ocean floor and detecting minefields. Additional sensors towed behind the ship eliminate blind spots. The sonar is primarily used to listen passively, but it can also transmit to satellites and communicate with internal weapons systems.

Captain’s tools
To pilot the sub into and out of port, Rexrode stands on the conning tower and navigates using waterproof binoculars with compass bearings, which are sealed and filled with nitrogen gas to prevent fogging. He also carries a handheld GPS and a portable laser rangefinder to determine the ship’s distance from the pier.

Digital nautical charts
In the past, sub crews plotted routes by hand, a laborious and time-consuming process. But the Missouri is equipped with a system that uses sensors and GPS to continuously update digital charts – and sounds an alarm if the sub veers off course or gets close to hazards. “I’ve seen lots of different ships with lots of different gear,” Rexrode says. “This is the best.”