Vigilant Forward Looking Sonar (Vigilant FLS)

    Navigate with confidence; reduces the risk of underwater collisions and groundings
    Long range hazard detection gives you time to change course
    Perfect for vessels of all sizes; commercial, military, cruise, exploration and private
    Compact design with mounting options to suit both new-build or retro fit
    Use it with our Sentinel intruder detection sonar for added protection
    Compatible with your existing bridge systems

    Venturing into unchartered waters? Vigilant FLS transforms your vessels underwater situational awareness.

    Imagine you had the equivalent of a parking sensor installed on the bow of your vessel. Imagine that it gave you a live 3D view of the seabed and the water column on your vessel heading. Imagine if that sensor also sent you automated warnings, when there was a collision hazard ahead, hidden from sight. Don’t imagine any more because Vigilant FLS provides you with all of this capability.

    Vigilant (formerly called NOAS) is our new long-range, forward looking sonar (FLS). It’s a compact navigation and obstacle avoidance sonar providing automated alarms of objects in the water column out to 1.5 km. It also creates – with unrivalled resolution and detail – a real-time, easy to interpret 3D terrain map of the seabed and water column ahead out to 600 m and down to 100 m water depth. Fit it to your vessel and you’re then prepared for anything, from seeking out a secluded bay, navigating busy shipping lanes or voyaging into the Arctic Circle to watch the Northern Lights. It’s also autonomous vessel ready.

    The system consists of a sonar projector and receiver array mounted in the vessel’s bow (or optionally on a retractable deployment pole) and bridge software. At just 31 cm-wide – comparative with a gaming console – and weighing only 14 kg in air (more than 90% lighter than our previous system), the sonar is easy to handle and install on a wide range of vessels, from exploration cruise, private yachts and naval ships, to harbour patrol vessels, offshore support vessels and research ships.
    Seaborne collision avoidance is also a vital consideration for autonomous ships and an ever-increasing number of unmanned surface and underwater vessels in the offshore energy, ocean science and naval market sectors. Vigilant can be integrated into these autonomous platforms to provide essential information to autopilots and command and control systems, to aid safe navigation and manoeuvres around hazardous obstacles.

    Vigilant has two principal operating modes, 3D mode and Sonar mode. 3D mode produces stunning 3D bathymetry and colour coded depth imagery using our proprietary Altitude Confidence Filter (ACF), out to 600 m and down to 100 m. Sonar mode processes the intensity of the acoustic data to extract long-range positional data out to 1.5 km and over a 90 degree field of view. In this mode, the sonar returns are used to generate alerts to the operator (or a third-party system) to the presence of a navigationally relevant obstacle.
    With its history mapping capability, a comprehensive picture of the underwater environment surrounding the vessel is built up, providing crews with greater situational awareness for tight manoeuvres or backing out of a confined area.
    Combined with our Sentinel intruder detection system, naval facilities and assets at anchor or in port can also protect themselves from underwater threats.

    Why Vigilant FLS?


    • Real-time determination of seabed terrain and under water hazards
    • Historical image display provides comprehensive situational awareness of the subsea environment
    • Easy to configure and operate; no need for sonar background
    • Overlay charts provide clear context
    • Configurations available for ships, unmanned surface and underwater vehicles, and SDVs


    • Receiver size (H x W x L): 110 x 310 x 401 mm
    • Projector size (H x W x L): 578 x 118 x 125 mm
    • Intuitive user software with touch screen interface
    • Seamless switching between Sonar and 2D/3D depth modes, and variable display ranges
    • User defined settings for warnings and automated alarm parameters
    • Electronic Nautical Chart (ENC) overlay (chart licence and permits not included)


    • Field of view 90°
    • Range 600 m in 2D/3D depth modes and 1500 m in sonar mod
    • Operating frequency 70 kHz
    • Operational speed up to 25 knots
    • Bottom mapping ratio up to 20 x water depth
    • Depth detection up to 100 m


    • What’s in the box: Projector and Receiver sonar arrays, cable assemblies, power and distribution cabinet, rack mounted marine computer, software
    • Warranty: 1 year return to Sonardyne service centre
    • ITAR Controlled: No
    • UK Export License: Not required

    More about this product

    Vigilant FLS Specifications & Datasheet

    Feature Specification
    Range / Field of View 75 m, 150 m, 300 m, 600 m x 90° 2D/3D Depth Mode
    75 m, 150 m, 300 m, 600 m, 900 m, 1500 m x 90° Sonar Mode
    Operational Speed Up to 25 knots
    Operating Frequency 70 kHz
    Bottom Mapping Ratio Up to 20 x water depth
    Maximum Depth Detection 100 m
    Roll/Pitch Stabilisation ±20°
    Angular Accuracy ~0.3
    Operating Power <150 Watts
    Operating Temperature -2 to 40°C
    Storage Temperature Range -20 to 55°C
    Receiver Height x Width x Length 110 x 310 x 400.5 mm
    Receiver Weight in Air/Water 12.0/6.0 kg
    Transmitter Height x Width x Length 577.5 x 118 x 124.5 mm
    Transmitter Weight in Air/Water 11.5/6.0 kg


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