The Sonar Operator: in the depths, the submarine’s eyes and ears

Listening to see

The sonar operators are the ones who anticipate. The ones who stay alert, even when the rest of the crew sleeps. 

They operate at the heart of the submarine’s Operations Center—a closed, dense environment, with no daylight. Those who, under artificial light and surrounded by consoles, listen to the outside world and translate it into decisions.

Their mission? To ensure the vessel’s navigational safety, and to contribute to the success of operations where even the finest trace detected could compromised everyone’s safety — and the mission itself.

Monitoring consoles. Rapid interactions. Controlled tension—their job is not passively watching the screens, it’s to build a mental image of an invisible, potentially hostile space. 

It means interpreting a complex array of signals from multiple antennas (towed, flank, interception...).

In a confined environment, with no windows and no visual landmarks, the slightest acoustic or frequency anomaly can be critical. When that happens—it’s time to decide fast and act.

Every trace, every audio variation may signal a threat—or an opportunity.
In front of them: surface ships, hostile submarines, asymmetric threats, underwater drones.... And sometimes… nothing. Hours of listening for a single meaningful signal.

The entire crew is committed to fulfilling multiple objectives: protecting sovereign interests, ensuring nuclear deterrence, conducting combat missions, engaging in anti-ship warfare, infiltrating and exfiltrating special forces, gathering strategic and tactical intelligence — and providing escort for aircraft carriers or naval task groups. 

All of it, supported by two types of submarines:

• SNA (nuclear attack submarine): redoubtable hunters of submarines and surface ships, capable of intelligence gathering, combat operations, and special mission deployment.
• SNLE (nuclear ballistic-missile submarine): highly furtive vessels, reputed to be virtually undetectable and invulnerable.

Vigilance to survive: rigour, listening, teamwork

A sonar operator’s life is measured in millimeters. On board, discipline is essential: watch shifts, sleep cycles, strict routines.

Stress peaks during complex maneuvers — surfacing transits, strait crossings, or returning to periscope depth. Each phase demands absolute vigilance. These profiles are rare. Each submarine is alternately crewed by two separate teams.

Before each mission, crews undergo land-based training on full-scale platforms. Operators rehearse critical scenarios in simulation: pursuit, evasion, torpedo attacks... Every deployment requires requalification, assessing each crew member’s ability to perform their role. If the level isn’t met, the submariner doesn’t sail. At sea, there is no room for approximation.

These requalifications are immersive: they replicate not only the rigor of procedures, but also the tension and focus required to execute them. Adrenaline, rapid exchanges, time pressure—everything mirrors real operational conditions.

Three roles, one continuous vigilance:

• The listener/ watchman: detects raw signals, anomalies, early traces.
• The classifier/ analyst: qualifies, compares, identifies.
• The coordinator: centralises, makes decisions, guides actions.

All are trained to detect the most subtle acoustic signatures. Requiering a trained ear, acoustic memory, procedural discipline—above all, the ability to perform under pressure and trust your team.

Together, they are the first line of the Operations Center. They detect, classify, analyse external acoustic signals. Thanks to them, the unit can build a reliable tactical situation (SITAC), navigate, maneuver—or prepare a response if the mission demands it.

Scenario: the tension of surfacing

Somewhere deep in the Atlantic Ocean, a submarine prepares to surface in order to transmit a critical message and intelligence. A brief but high-risk phase. Anything can happen: a collision with an undetected vessel, water ingress… Transition phases are always critical.

Inside the Operations Center, comms intensify. Tension builds as the moment draws closer. The coordinator gives the orders. The classifier confirms: cargo vessel, heading 090, moving away. Situation clear. Ready to regain visual contact.

Surfacing begins. Suddenly—an alert. Mechanical noise. A diesel engine, and the distinctive clatter of fishing gear. A trawler.

Immediate reaction from the commander: “Dive to 100 meters. Pitch negative 20°. Rudder 5° right. New heading 240.” Priority: break contact with the fishing vessel.

Just a few seconds to grasp the situation, issue the right orders, and recover safe depth—protecting both the submarine and the trawler.

The submarine is blind. Sonar operators listen to see. They build a mental map of the tactical and environmental picture. Preventing an accident is mission-critical—and vital for survival. A submarine can easily drag down a fishing boat.

At every moment, one rule stands above all: maintain the safety volume—a vertical buffer of water that allows the submarine to surface or dive at any moment, instantly, and without collision.

Evolving tasks

The undersea battlespace is evolving—threats are rising fast: drones, passive sensors, and asymmetric threats and tactics.

Facing ever more advanced adversary technologies, operators must stay highly skilled and agile—through ongoing trainings, certifications, and constant adaptation to a shifting operational landscape.

To maintain full operational readiness, submarines are equipped with reliable and mission-ready systems, all designed to deliver maximum combat effectiveness, including:

• Combat Management System
• TUUM, the submarine’s “telephone,” used to send and receive orders and intelligence
• Operator consoles designed for a confined, dark, and unstable environment
• Active and passive sonar systems
• Onboard data centers
• Various antennas depending on the types of detection...

Designing for them: UX in a closed and tense world

In the Operations Center, every pixel, every equipment, every feature counts. Interfaces and hardware must be readable at a glance, usable under low light, and responsive in urgent situations.

Designing for sonar operators means understanding their rituals, their priorities, and translating acoustic complexity into reliable, comprehensible signals. Design truly serves operational efficiency, and understanding these ultra-technical environments is particularly complex.

On-land explanations are never enough, but it is rare to get on board a submarine outside official visits. To capture the operators’ insights, UX designers conduct on-land interviews and more importantly observe trainings on ESNA’s (Nuclear Attack Submarine Squadron) full-scale platforms, faithfully reproducing real conditions. These platforms are configured like real Operations Centers. For a designer, attending these sessions is a striking immersion: rising tension, efficient coordination, rapid exchanges—a unique experience.

In the submarines, sonar operators listen to see, analyse to protect, and take decisions to survive. They ensure the vessel remains stealthy, in command of its trajectory, and ready for any contingency. Designing for them means contributing to operational superiority—and carrying a responsibility in line with their dedication.