When GNSS Can’t Be Trusted: Why Resilient Navigation Matters

GNSS interference is no longer only a theoretical navigation risk. Jamming and spoofing are already affecting vessel operations in several challenging maritime regions, making resilient position and timing data increasingly important for bridge teams and connected onboard systems.

Position data supports more than navigation

A vessel’s GNSS position is not used by a single isolated display. Accurate position and time can feed multiple systems across the bridge and wider vessel network, including radar, ECDIS, AIS and VDR. Other onboard equipment may also depend on reliable position or timing information for correct operation.

This means that GNSS disruption can create a wider operational problem than the loss of a single navigation source. The challenge is maintaining confidence in the data being distributed across the vessel when the external signal environment becomes unreliable.

Real conditions, not only laboratory tests

SEALINK has been running production, integration and field-testing programs with systems operating onboard customer vessels. According to the company’s field updates, deployments have included the Baltic Sea, Black Sea and Middle East, including areas affected by severe GNSS interference.

The purpose of this work is to validate resilient positioning and timing under the conditions crews actually encounter, rather than relying only on controlled testing environments.

Resilience starts with visibility

Modern navigation resilience is not only about maintaining a position output. It is also about giving operators better awareness of the integrity of the signals and data they are using. Detecting interference, understanding when conventional GNSS may be compromised and maintaining reliable alternatives can help bridge teams make better-informed decisions.

As GNSS interference becomes a recurring operational concern, resilient navigation is moving from a specialist requirement toward a practical part of modern vessel safety and system design.