U864 Counterfill


The German submarine U-864 sunk off the coast of Norway during World War II. The submarine was on its way from Germany via Norway to Japan and was carrying about 67 metric tons of mercury.The wreck of U-864 was rediscovered by the Norwegian Navy in 2003, resting on the seabed at a depth of 150 metres. It has broken into two large sections.

To prevent any further mercury contamination into the environment the Norwegian coastal administration (NCA) is taking as a first step to monitor the risk of mercury spreading into the environment and to install a counter fill on the seabed to stabilize the broken parts of the submarine.

Stringent requirements have been set for environmental monitoring of the work. Develogic is part of the project team which involves Van Oord, the Norwegian Institute for water research and the Norwegian Geotecnical institute. For this projects develogic developed 10 underwater measuring platforms with different sets of sensors and a highly sophisticated underwater communication system. This includes an inductive system which integrates all underwater platforms with sensors and as an additional communication line: an acoustic backup.

This enables to monitor important safety parameters in real time: turbidity and current, as a proxy for the possible spreading of contamination. Also with sets of two different sensors develogic is able to monitor any movement of the instable submarine wreck. All incoming data are accessible via a satellite link by a large spar buoy, which was especially designed by develogic for this project.

The public can follow in real time the whole process by observing the incoming data stream on a geoview webpage of the Norwegian Institute for Water Research.

With this project develogic sets new standards for large scale and highly complex underwater communication systems with integrated measuring platforms and it facilitates the save operation of this project.

Read the full article published in the February 2017 issue of the Sea Technology magazine here

Monotoring System Detects Possible Mercury Contamination



DAMOCLES (Developing Arctic Modeling and Observing Capabilities for Long-term Environmental Studies) is an integrated ice-atmosphere-ocean monitoring and forecasting system designed for observing, understanding and quantifying climate changes in the Arctic.

As part of this project there are currently three develogic HAM.NODE Hydro Acoustic Modems deployed in a mooring assembly across the Fram Strait between Svalbard and Greenland. Another HAM.NODE system with satellite data communication link is pending.

The HAM.NODE modems transmit sensor data from Aanderaa current sensors between neighboring moorings that are spaced up to a maximum distance of 30,000m from each other. Data transmission is performed using our advanced n-mFSK modulation scheme and a LF ITC-2002A transducer with toroidal beam characteristic. The typical net user data rate with this setup is about 145bps @ 30,000m horizontal.

For this project all HAM.NODE modems were installed in custom pressure housings with integrated Li-SOCl battery packs and pressure relief valves. Custom mooring frames with 40kN operating load ensure convenient deployment and safe installation within the moorings

GITEWS – Acoustic Link for Seismic and Bottom Pressure Data


GITEWS (German Indonesian Tsunami Early Warning System) is a project of the German Government at the reconstruction of the tsunami-prone region of the Indian Ocean. The sensors of this system comprise seismometers, GPS instruments, tide gauges and buoys as well as ocean bottom pressure sensors.

After extensive benchmarking of various international competitors, the develogic HAM.NODE Hydro Acoustic Modem was chosen as the sole subsea communication system for transmitting sensor data from the ocean bottom to the surface data buoys.

The HAM.NODE surface modem is installed in a custom mooring frame below the data buoy and relays sensor data from the bottom modem to the buoy controller.

For lower operating cost the surface modem is powered from re-chargeable NiMH batteries. Charge management is handled by the optional HAM.NODE Power Management Module.

The bottom modem is mounted to an ocean bottom unit and directly interfaces to a Paroscientific precision depth sensor and a SEND Geolon MTS seismic recorder system. The bidirectional transmission of sensor data between bottom and surface modem is per-formed using OFDM-mDPSK modulation with MF directional transducers. Typical net user data rates up to 3,400bps can be achieved with this setup across near vertical channels of up to 6,500m depth.

Besides conducting data transmission, the customizable application layer of the HAM.NODE bottom unit also records pressure data and is responsible for detecting tsunamis on the recorded pressure data.



Modoo (Modular Deep Ocean Observatory) is a demonstration Mission of a modular and mobile deep ocean observatory which will be oparated at the Porcupine Abyssal Plain (PAP), 350 nm off southwest Ireland.

Develogic provides the core data logging and HAM.NODE based telemetry unit for the lander with interfaces to 6 different instruments (including a digital still camera) as well as the mooring unit that communicates via an inductive modem with the surface system provided by the NOC Southampton.



This EU-project is about oxygen monitoring in aquatic ecosystems. One sub-project is to find out the effect of bottom water renavel on climate driven hypoxia in Sea Loch Etive, Scotland, with limited exchange. The cabled observatory is equipped with key telemetry components from us (lake bottom communication hub based on MiniLogger, MCH housing, mooring frames, lake shore telemetry cabinet with internet uplink / LCOM software).

The system was successfully deployed in November 2009.

West Nile Delta Project


The West Nile Delta Project is a study about mud volcanos underneath the west Nile delta. Two bottom units featuring HAM.NODE modems are deployed as surface telemetry systems.

PACT – Pressure Based Acoustically Coupled Tsunami Detector


In the framework of the GITEWS project for establishing a Tsunami Early Warning System in the Indian Ocean, the German Alfred-Wegener-Institute for Polar and Marine Research develops PACT (Pressure based Acoustically Coupled Tsunami Detector) – a compact and low cost bottom unit for acquiring and relaying precise bottom pressure data. The real-time data are transmitted acoustically to the surface bouy, and further via a satellite communication link to a Tsunami Warning Centre for verification and eventually alarm announcement.

The PACT ocean bottom unit is contained within a single glass sphere (47cm diameter) with an operating time of at least two years. Development of the bottom unit is performed under lead management of the German company Optimare, Bremerhaven, while develogic supplies the acoustic data communication hardware.

A HAM.NODE OEM modem has been customized and integrated into the PACT bottom unit and interfaces with an integrated third party system controller. Bottom pressure and diagnostic data is transferred bidirectionally between the HAM.NODE bottom unit and a HAM.NODE surface modem using n-mFSK modulation with MF omnidirectional transducers. Net user data rates are tested up to approx. 600bps across a near vertical channel of ~6,600m average distance.



The DOLAN mooring assembly was located 60 nm north of the Canary Islands and had been installed in framework of the terminated project ”Data transmission in the ocean and lateral acoustic net-work in the deep sea”.

In November 2007 a PACT ocean bottom unit was deployed to a depth of 3,300m in vicinity of the DOLAN mooring. The system was equipped with a HAM.NODE OEM Hydro Acoustic Modem communicating with a HAM.NODE surface modem installed at the DOLAN data buoy. A HAM.ISDB Iridium Satellite Communication Module relayed the bottom sensor data to the AWI in Bremerhaven, Germany.

During its adoption the system proved a transmission re-liability rate of better than 98% across a near vertical distance of 3,900m average, even under heavy weather conditions.



The THOR lander acquires ocean current, CTD and oxygen content data for climate research purposes. The lander was deployed in the Faroe Bank Channel by Bjerknes Centre for Climate Research and Geophysical Institute (Bergen-Norway). The rirst data were successfully downloaded to a surface vessel in June 2010. It utilizes develogic HAM.Node modems for data logging and transmission. The maximum deployment duration is 5 years. The data will be downloaded several times a year.

develogic delivered acoustic telemetry for THOR lander.

Download:        Telemetry systems to access climate sensitive data from moodes instrumentation