First and only platform using EM fields to connect networks above the water with digital devices under water, without cables

OCEAN BUSINESS (STAND W89), SOUTHAMPTON, ENGLAND – April 18, 2023 – CSignum Ltd., the global leader in cable-free underwater communications and actionable insights for ocean and freshwater industries, today publicly demonstrated its new EM Modem™ at Ocean Business in Southampton. Available today and successfully deployed in partner trials, EM is the first platform to use low-frequency electromagnetic (EM) fields, nature’s perfect through-the-surface energy to transmit more data wirelessly from more places than is possible with cable, acoustic, and optical.

EM is the only technology that can transmit data through the water-air boundary, water column, seabed, and subsea structures, as well as connect digital devices in networks below the water with those networks on land and in the air. EM signals are resilient sustaining their integrity where sound and light scatter: at the surface; in shallow splash zones; aerated, turbid and bio-fouled waters; and, anywhere ambient light, line of sight and noise interference is an issue. Because EM fields are also silent and invisible, they are more secure as well as safer for the environment and marine life.

“We expect EM to become the cable-free gateway for marine data through the surface of the water,” said Chris Brooks, CEO of CSignum. “EM is already successfully deployed in a multitude of use cases from AUV/ASV (HESS and Ocean Aero) and tidal water data recovery to offshore structural and met ocean data transmission to real-time ADCP data. EM has reliably sent data at a range of 28-30m via underwater modems to topside receivers transmitting at 200bps. The battery life is phenomenal, too, enabling up to 3 months on standard external rechargeable batteries before needing a recharge or replacement.”

CSignum is focused on helping environmental, aquaculture and industries using subsea structures such as wind farms, fisheries, and a range of coastal resiliency programs modernize their data collection operations. The EM-1 Modem is designed to work seamlessly with the standard interfaces of sondes, sensors, AUVs, ADCPs and dataloggers, and optimizes power consumption and battery life, reducing the need for routine maintenance and improving sustainability.

A recent sonde to shore demonstration in port with a major energy customer to 30 European customers successfully showcased the power of EM for the wind farm and environmental industry reliably sending transmissions from underwater to quayside.  Wind farm equipment suppliers require continuous access to data showing the impact of conditions on the structural integrity of their platforms, as well as determining remaining asset life. Operators do not have easy access to this data today, requiring teams of divers to retrieve data and visually assess structures, causing unnecessary downtime, inefficiencies in performance, and potential health and safety risks. With EM, operators can monitor fatigue, corrosion, strain, pressure, temperature and currents in real time.

CSignum’s second generation of the EM Modem, available mid-2024, will continue to push the boundaries of underwater electromagnetic transmissions enhancing range and data rate, and expanding data interfaces to support RS-485, SDI12, and others. Additional features will include repeater protocol, advanced networking, single bit signallng, and edge computing.


The CSignum EM Monitor version 1.0 is available now for commercial sale. To receive additional information about the product or to see a demonstration or initiate a trial, please go to  EM1 – CSignum

About CSignum Ltd

CSignum is the pioneer in a new cable-free data communications solution known as EM that uses patented low frequency electromagnetic (EM) fields to enable the autonomous and reliable transmission of data through and across the water-air boundary, water column, seabed and underwater structures to networks on land and in the air. The EM communications platform and EM-1 modem help environmental, aquaculture and subsea structure industries transmit data as they digitally transform and scale remote communications systems for greater sustainability, increased performance, and preparedness for unforeseen events.

CSignum was founded in 2020 and is headquartered in Bathgate, Scotland.

Media Contact:

Jessica Kersey

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