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Sentinel sonar frames and loudhailer

Sentinel IDS accessories

Engineered for: Diver

One of the most popular methods to deploy Sentinel is our modular, quick-to-assemble seabed frames. Add on our underwater loudhailer to provide an audible deterrent if intruders are detected.

At a glance

Popular accessories for our Sentinel Intruder Detection Sonar

Seabed frames; choice of two designs, easy to transport and assemble

Perfect for expeditionary, training and temporary vessel-based operations

Scylla; Non-lethal loudhailer warns intruders away

Can play pre-recorded and live messages

Product At A Glance Cta Title

Product At A Glance Cta Description


Developed by our sister company Wavefront Systems and manufactured and commericalised by Sonardyne, Sentinel seabed frames are available as either standard or lightweight versions; both of which allow the rapid and stable deployment of a Sentinel sonar head on the seabed.

Both frames are constructed of high-grade aluminium and have user replaceable sacrificial zinc anodes attached to prevent corrosion. The frames break down into manageable pieces – each weighing less than 8kg – and are easily reassembled.

Frames are supplied with a single 5kg (11lb) weight per leg, but in difficult environment conditions, such as high current areas, additional weights can be easily added. An optional mud plate can also be attached to the base of the frame to prevent the system from sinking when deployed on a soft seabed.

Using the deployment strops the frame can be lowered onto the seabed by using a small davit or crane.

Scylla loudhailer
Scylla is an optional module for Sentinel which adds an underwater audible warning and deterrent capability. Scylla comprises an underwater speaker and a surface loudhailer drive unit (LDU).

Scylla system has been designed such that the maximum source level does not exceed 195 dB re 1µPa @ 1 metre. Trials and modelling have shown this sound pressure level is to be disorientating but not dangerous to humans even if divers approach to within one metre of the underwater speaker.

Scylla can be co-located with the Sonar Head and controlled via the standard 75 m or 300 me sonar cable or deployed remotely via a dedicated cable, allowing easy over-the-side use.


Feature Type 8165-015-01 Standard Frame Type 8165-013-01 Lightweight Frame
Dimensions (Width x Height) 2,145 x 1,424 mm 1,192 x 729 mm
Weight in Air 31 kg + optional foot weights 16 kg + optional foot weights
Number of Sections 7 4
Type 8165-022-01 Loudhailer Type 8165-022-01 Loudhailer Driver Unit
Frequency Response 250-20 kHz
Source Level (dB re 1 µPa @ 1 m) 195 dB (maximum)
Dimensions (Diameter x Width) 230 mm x 150 mm 482 x 176.9 x 86.5 mm (19 x 7 x 3.4”)
Weight 5.4 kg 4 kg
Maximum Operating Depth 15 m
Power Supply 115/230 V ac, 6/3 A, 50/60 Hz

Enhance your Sentinel IDS installation

Enhance your Sentinel IDS installation