AQUAmodem® Op2

Optical modem system for short range subsea data transfer – to 3500m

Ideal for use with ROVs

The AQUAmodem Op2 is an advanced optical modem that provides a seamless interface between the user and any subsea instrumentation with RS232 serial interfaces, such as our AQUAlogger oceanographic instruments and HYDROlog hydrotest loggers. The connection is made typically via an ROV umbilical, providing simple use and deployment of the instrument. The AQUAmodem Op2 features individual unit addressing and automatic optical or serial data wake-up, to conserve the life of the external battery pack and prolong the service of the device. The instrument permits short-range interrogation, commanding, and data download for your subsea monitoring equipment, providing you with a cost-effective and efficient solution to solve your subsea communication needs.




Innovative design

  • Users can benefit from having access to data subsea, which can be particularly useful at times when it is impractical to retrieve the monitoring instruments.
  • The AQUAmodem Op2 has real-time capability (depending on your monitoring instruments), which can save you time and money in the field, and allows for prompt analysis of data.

The safe and simple solution for underwater data transfer

  • The AQUAmodem Op2 is a cost-efficient alternative to wetmate connectors. As the AQUAmodem Op2 negates the need for permanent cables, operators can benefit from greater flexibility in the deployment of their instruments.
  • Once installed, the AQUAmodem Op2 will wirelessly transfer your information ready for analysis.

Ideal for use with ROV

  • The instrument is designed to transmit data through the ROV umbilical cable, giving simple deployment and operation. Alternatively, the AQUAmodem Op2 can be deployed by divers.


  • The AQUAmodem Op2 is compatible with any instrument with an RS232 serial interface, including Aquatec’s AQUAlogger and HYDROlog ranges.

Ready to use

  • We supply you with everything you need to get started, including an external battery, subsea cable, test cables and manuals.

Technical specification


Operating Depth

3500 m


Operating: -5°C to 40°C
Storage: -40°C to 65°C


Light Band

Cyan visible light

Operating Range

Typically 1 m depending on environment

Transmission Type

Digitally coded telemetry with error detection

Typical Maximum Data Throughput

10.2 kBytes/s


Up to 3 unique addresses, plus a universal / broadcast address



285 mm long by 72 mm max diameter; main housing diameter 60 mm


4 kg in air, 3 kg in water


Stainless Steel 316 with Perspex window


External Power

ROV unit 9 - 36 Vdc

Subsea unit 6.5 - 32 Vdc

Wake Up

Serial Wake Up

Optional on receipt of RS232 serial data for subsea unit

On receipt of RS232 serial data for ROV unit

Optical Wake Up

On receipt of optical interrogation



RS232 levels


Any format – transparent link

Baud Rate

115200 baud


Q: Is the modem set up for one or two-way communication?

The AQUAmodem® Op2 is designed to be used to transfer data from an instrument subsea, without the need for a subsea connection. Under the standard application, one modem would be connected to an instrument gathering data. The other would be connected to an ROV or held by a diver, and be used to ‘wake up’ the first modem and receive the transferred data.