Subnero S40H Series Silver Edition high-frequency (HF) acoustic smart modem in side profile, showing its compact underwater housing and connector Subnero S40H Series Silver Edition HF acoustic smart modem mounted upright on its base, showing the underwater connector and cable Disassembled Subnero S40H Series Silver Edition modem showing its internal electronics stack, processing board, and transducer components Two Subnero S40H Series Silver Edition acoustic smart modems standing on a railing with a harbor in the background, ready for high-speed underwater deployment
Subnero S40H Series Silver Edition HF modem thumbnail – side profile view Subnero S40H Series Silver Edition HF modem thumbnail – upright mounted view Subnero S40H Series Silver Edition HF modem thumbnail – disassembled internal components Subnero S40H Series Silver Edition HF modem thumbnail – dockside deployment view
Gen4x
Silver Edition
HF Band

S40H Series

25 - 50 kHz Band

The Silver Edition S40H series modem represents a breakthrough in high-speed underwater acoustic communication. Designed for high-throughput data transfer, it enables applications that were once impractical in the subsea domain — such as wireless camera image transmission, rapid sensor data exchange, and real-time connectivity for marine robotics over short ranges. The S40H series serves as a stepping stone toward true high-speed underwater networks, bringing the performance and flexibility of modern digital communication to the ocean environment.

Applications

  • Wireless image transfer for inspection and monitoring systems
  • High-speed data offload from subsea instruments, AUVs, or sensor arrays
  • Near real-time connectivity for marine and subsea robots
  • Short-range underwater IoT and testbed networks for research and development

Key Features

  • High-speed data rates up to 33 kbps* in shallow tropical waters.
  • Communication range up to 1 km (horizontal and vertical).
  • Built-in ranging with 0.1 m precision for accurate positioning.
  • Doppler resilience of ±4 knots ensuring stable performance in motion.
  • Compact and lightweight design for seamless platform integration.
  • Fully software-defined architecture using UnetStack.

* Depending on channel conditions and reliability requirements.

Subnero S40H Series Silver Edition high-frequency (HF) acoustic smart modem shown at an angle with its protective transducer cage and connector

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-S40HSS4X

Subnero WNC-S40HSS4X Standalone Configuration Preview

Standalone Configuration

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

WNC-S40HSO4X

Subnero WNC-S40HSO4X 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 S40H Series Underwater Modem brochure Subnero S40H 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 25 kHz (25 - 50 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
Mechanical
Feature Details
Hull material Aluminum
Depth rating 300m
Dimensions SC: ø 100 x 294 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.

View Details →
MF Band

M25M Series

20 - 32 kHz band

Versatile connectivity for diverse set of applications.

View Details →
HF Band

S40H Series

25 - 50 kHz band

High-speed connectivity for data-intensive underwater applications.

View Details →
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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