Subnero M25M Series Silver Edition medium-frequency (MF) acoustic smart modem mounted upright on its base, showing the underwater connector and antenna Subnero M25M Series Silver Edition MF acoustic smart modem mounted upright with dual underwater connectors and cables for multi-channel integration Disassembled Subnero M25M Series Silver Edition modem showing its internal electronics stack, processing board, and transducer housing components Subnero M25M Series Silver Edition acoustic smart modem being deployed by hand from a dockside during a field trial
Subnero M25M Series Silver Edition MF modem thumbnail – upright front view Subnero M25M Series Silver Edition MF modem thumbnail – upright view with dual connectors Subnero M25M Series Silver Edition MF modem thumbnail – disassembled internal components Subnero M25M Series Silver Edition MF modem thumbnail – dockside field deployment
Gen4x
Silver Edition
MF Band

M25M Series

20 - 32 kHz Band

The Silver Edition M25M series modem is the dependable workhorse of the Gen4X series, designed for versatility across a wide range of underwater communication applications. Balancing data rate, range, and robustness, it provides a reliable foundation for subsea networks, marine robotics, and sensor platforms. With a software-defined architecture built on UnetStack, it enables easy customization of protocols and algorithms to suit mission-specific requirements.

Applications

  • High-performance, all-rounder modem for oceanographic and commercial deployments
  • Subsea sensor networks for offshore monitoring
  • Marine robot integration for telemetry and control
  • General-purpose underwater research and testing

Key Features

  • Data rates up to 15 kbps* in shallow tropical conditions.
  • More than 4 km communication range in littoral waters.
  • Built-in acoustic ranging with 0.1 m precision.
  • Doppler resilience of ±4 knots or better.
  • Support for coherent and incoherent communication schemes.
  • Arbitrary signal transmission as well as recording (passband, baseband).
  • User-defined communication schemes using UnetStack.
  • Compact and rugged form factor suited for versatile integration.

* Depending on channel conditions and reliability requirements.

Subnero M25M Series Silver Edition medium-frequency (MF) acoustic smart modem shown at an angle with its protective transducer cage, connector, and cable

Flexible Configurations

Available in standalone, and open configurations to suit a range of deployment needs—from self-contained setups to integrated and high-performance systems.

WNC-M25MSS4X

Subnero WNC-M25MSS4X Standalone Configuration Preview

Standalone Configuration

Self-contained modem powered by an external battery or power supply.

WNC-M25MSO4X

Subnero WNC-M25MSO4X Open Configuration Preview

Open
Configuration

Integration-ready electronics for AUVs, ROVs, and sensor platforms.

Standalone Configuration (SC)

The standalone configuration (SC) features a pressure-rated housing designed for operation at various depths, powered externally via batteries or through a surface power supply. This configuration is ideal for fixed or moored sensor nodes, seabed installations, coastal monitoring stations, or surface-deployed relay systems, where ease of deployment and reliability are critical.

Open Configuration (OC)

The open configuration (OC) streamlines integration and enhances adaptability, making it ideal for incorporation into subsea platforms such as marine robots, autonomous systems, and larger sensors. It supports seamless electrical and software integration for platforms. This configuration is well suited for AUV- or USV-based missions, and payload integration within custom subsea assemblies, providing flexibility without compromising performance.

Brochures

Subnero M25M Series Underwater Modems brochure Subnero M25M Series Underwater Modems

Useful Links

WNC Product Series

Technical Specifications

Communication
Feature Details
Modulation (software defined) PSK-OFDM, FH-BFSK
FEC (Forward Error Correction) LDPC, BCH, Convolution code
JANUS support Yes, subject to operating frequency band
Bandwidth 12 kHz (20 - 32 kHz)
Software
Feature Details
Framework UnetStack
User Interface Interactive web UI
Software Interfaces Java, Groovy, Python, C, JavaScript, Julia, JSON/TCP
Electrical
Feature Details
Power source 18 - 30 VDC (24 VDC recommended)
Power consumption < 4 W (receive mode, nominal)
< 45 W (transmit mode, avg.)
< 200 mW (sleep mode)
< 5 mW (deep sleep mode)
Wake up modes Acoustic wakeup, External electrical interrupt, Scheduled wakeup
External interface Ethernet (10/100 Mbps), RS232*
On-board storage 256 GB, 1 TB
Receive channels 1, 2 (configurable at the time of purchase)
Mechanical
Feature Details
Hull material Aluminum, Stainless steel, Titanium
Depth rating 300m, 2000m, 4000m, 6000m
Dimensions SC: ø 100 x 303 mm, OC: ø 88 x 137 mm
Operating temperature SC: 0 to 40 °C, OC: 0 to 70 °C (electronics) 0 to 40 °C (transducer)
* Different cable required for RS232 connection.

Quick LInks

LF Band

L12L Series

9 - 16 kHz band

Long-range, acoustic communication for persistent presence.

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MF Band

M25M Series

20 - 32 kHz band

Versatile connectivity for diverse set of applications.

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HF Band

S40H Series

25 - 50 kHz band

High-speed connectivity for data-intensive underwater applications.

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Gen4X

Components, Accessories & Optional Upgrades

Expand functionality with modular components, accessories and upgrades.

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Legacy

Gen4 WNC Series

Trusted technology continuing to support ongoing deployments.

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