Relying on electromagnetic fields means EM-1 signals easily pass through the surface of water instead of scattering like sound and light waves. In fact, devices signaling with cable-free, highly resilient EM-1 also transmit reliably through the water column, seabed and subsea structures. Paired EM-1 modems can be mounted on piles, buoys, nets, or pontoons above, on or below the water and do not require line-of-sight placement.

Transmission from Sensor to Shore

Ideal for deployments and applications in the splash zone and shallow water environments, where adverse conditions may exist, the EM-1 is designed to pair with underwater sensing systems, enabling cable-free connections from below water to topside EM-1s paired above the waterline. Compatible with sensing systems such as multiparameter sondes and ADCPs, EM-1 modems use industry standard data interfaces like RS-232.

EM-1 Value Over Existing Solutions

As the first and only reliable cable-free data transmission through the surface of water, EM-1’s using EM-1 unlock flexible placement and movement of underwater digital devices in and between more locations.

  • Cables often become snagged and fail due to repeated stresses from wave motion
  • Acoustic signals bounce off the surface and are degraded in turbid or choppy water
  • Optical solutions scatter signals at the surface while underwater they require line of site, are effected by biofouling and are degraded by ambient light and turbidity


  • Performance is unaffected by biofouling, turbidity or environmental noise in the water column and does not require line of sight
  • It’s totally invisible and totally silent, so there are no adverse effects on aquatic life or use in security systems
  • Bidirectional point-to-point communication is available today; multi-point connectivity and relay capability planned for the future

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