ASI Hydro is a joint venture marine service(s) company between DS Group and ASI Group Ltd. (ASI Marine), a world leader in flooded tunnel inspections. This joint venture allows ASI Hydro to provide industries and governments worldwide with leading-edge underwater services focused on the assessment, maintenance, rehabilitation, and construction of underwater infrastructure. Specifically, ASI Hydro specializes in underwater remotely operated vehicle (ROV) operations, and marine geophysical and hydrographic surveys.  

Our underwater ROV operations take place in both contained environments (e.g., inside tunnels, pipelines, etc.) and non-contained open water environments (e.g., dock/dam inspections, pipeline/cable route inspections, intake/outfall inspections, target identification, etc.).

Our divers, construction crews, engineers and technicians are backed by a fleet of advanced robotic vehicles; providing the latest in sonar and video imaging, survey and inspection technologies. ASI Group has earned an international reputation for the highest standards of quality in serving municipalities, hydro power producers, refineries, manufacturing industries, mines and pulp and paper mills.

ASI’s extensive ROV experience combines knowledge and technology to provide remote services that give our clients the data they require to make critical decisions and solutions to solve their problems.

Industries served:

  • Power Generation (Nuclear and Hydro)
  • Industrial
  • Commercial

Alejandro Peña
Gerente ASI Hydro Ltda.
+56 9 8501 0930

Barros Arana 424 – Cerro Esperanza
Valparaíso – Chile

+56 (32) 2215174

ASI’s Remote Services include:

ASI Group is the world leader in inspections of long water conveyance tunnels using Remotely Operated Vehicles (ROV’s). Tunnel inspections utilizing ROV technology provide:

  • Identification of voids, crack, leaks and other anomalies affecting structural integrity
  • Tunnel / pipe metal thickness measurement
  • Volumetric assessment of accumulated debris or sediment
  • Critical data for decision making for outages and remediation strategies
  • Eliminating the need for costly plant shutdowns and tunnel dewatering
  • ASI’s tunnel experience optimizes the combination of equipment and inspection protocols to satisfy project goals efficiently with consistent quality

Each vehicle in ASI’s ROV fleet has the longest distance capabilities of their class worldwide. Our unique tunnel inspection experience and underwater robotic capabilities have earned ASI a place in the Guinness World Book of Records, records which remain unchallenged.

3D Mapping for Condition Assessment. New and innovative technologies enable ASI Hydro technicians to collect point cloud data and produce unique and remarkable 3D visuals allowing clients an easy, clear and accurate understanding for their condition assessment.

ASI Hydro’s capability to perform mapping of submerged infrastructure adds great benefits to generating a complete condition assessment, with the ability to create baseline and comparative surveys. Inertial Navigation coupled with acoustic profilers allow for production of complete, geo-referenced data sets. 3-dimensional maps of pipelines and tunnels can be constructed for real-time display and processed deliverables.

ASI Hydro works with clients to assemble a custom suit of equipment and technologies to meet project requirements. During an investigation, data collection is displayed in real-time to aid in navigation and to allow the technician to make instantaneous analysis of the infrastructure. Recorded information is used to generate detailed reports including graphics and models of the assets.

Detailed reports in various formats allow clients a greater understanding of their asset’s condition and, assists clients in making decisions relating to cost effective maintenance programs.

ASI Hydro owns and operates a diverse fleet of advanced remotely operated vehicles (ROV’s) that services a wide range of industries. Combined with the latest in video capture and sonar imaging, specialized ROV tooling and inspection techniques, ASI’s ROV Service has earned international reputation for the highest standards of quality.

ASI has proven the viability of Remotely Operated Vehicle (ROV) inspections as a safe and cost effective technology to determine condition assessments of underwater assets. ASI has gained international recognition for research and development of remote techniques for underwater inspection and maintenance and welcomes the opportunity to handle complex technical assignments in challenging underwater environments.

Our ROV fleet includes a wide range of vehicles capable of carrying various sensor or tooling packages to meet the inspection and maintenance needs of our clients. ASI’s extensive experience using ROV’s in various applications, combines knowledge and technology to provide remote services that give our clients the data they require to make critical decisions and solutions to solve their problems.

Inspection and maintenance is critical to the performance and longevity of underwater infrastructures. As technology has evolved, inspections of these structures are possible with use of commercial divers and robotic vehicles. However, these methods may require costly shut down periods. As a result, ASI Marine has designed and built specialized sonar systems capable of collecting pertinent data in flow conditions.

Using advanced sonar technology provides accurate dimensional information regarding the structure condition and accumulated debris. It can be used to obtain 2D or 3D information of any underwater infrastructure or object, including flooded shafts, intake structures, spillways, dams and penstocks, all while under operational conditions providing important data showcasing what lies beneath the surface in a clear and precise graphic representation.


  • Eliminate costly shutdowns.
  • Monitor silt and debris accumulation, scour, and erosion in hazardous conditions.
  • Observe collapse or undercutting occurrences, therefore enabling corrective action.
  • Provide a remote measurement of infrastructure

ASI Hydro’s underwater mapping services employs a combination of hydrographic, marine geophysical, and visual inspection techniques to conduct thorough underwater investigations. Using a combination of geophysical mapping and charting technology, ASI Marine is able to locate the submerged surface features and targets in question, addressed by clients. These findings are measured and mapped with precision accuracy in real-time. ASI Marine’s in-house certified hydrographers, cartographers and graphic specialists produce detailed technical reports (hardcopy and GIS compatible formats) utilizing geophysical data acquired during the underwater investigations allowing clients to make informed decisions for asset management and/or engineering purposes.

ASI Hydro’s personnel have both domestic and international experience with over 40 years of providing geophysical services. This, combined with ASI Marine’s extensive inventory of the latest geophysical equipment, enables us to provide a broad range of techniques to conduct any underwater investigation.

The suite of marine geophysical services available include:

  • Marine geophysical surveys utilizing side scan sonar, sub-bottom profiling, bathymetry and positioning
  • Geological investigations
  • Habitat mapping and archaeological surveys
  • Underwater search, survey and recovery
  • Dredging surveys and volumetric determination
  • Sonar profiling/imaging surveys
  • Open-water remotely operated vehicle (ROV) inspections
  • Integrated navigation and positioning services
  • Cable and pipeline inspections
  • Unmanned survey vessel (USV) inspections

Technologies used for ASI Hydro Geophysical and Hydrographic Services include:

  • Single-beam and Multi-beam Bathymetry – provides precise water depth measurements allowing generation of 2D and 3D underwater mapping.
  • Side Scan Sonar Surveys – provides an acoustic “aerial photo-like” 2D image of the seabed/riverbed/reservoir bed.
  • Water Current Data Collection – Acoustic Current Doppler Profiler (ADCP) Deployments. Provides high accuracy current profiling data and complete water column sampling. By using for four transducers, the direction of the water particles can be determined as well as their velocity.
  • Navigation and Positioning Services – Differential Global Positioning Systems (DGPS) – real-time kinematic (RTK) centimetre accuracy systems as well as sub-metre accuracy systems depending on the requirement.
  • Marine Magnetometer Surveys – used to detect ferrous metals on or under the seabed/riverbed/resevoirbed.
  • Sub-bottom Profiling – Industry standard technique for the collection of data concerning shallow geological and sedimentary conditions below the seabed/riverbed/resevoirbed providing valuable insight into the nature of the sub-bottom.
  • Sediment Sampling – Dependent on the bottom type and water depth, a drop core sampler or a grab sampler (e.g., Ponal sampler) can be used. Samples can then be analyzed for contamination, grain size analysis and geotechnical properties.

Benefits of Sonar Surveys:

  • Remote target identification
  • Monitoring of silt and debris accumulation, scour and erosion in hazardous conditions
  • Observation of collapse or undercutting occurrences enabling corrective action
  • Remote measurement of infrastructure

Industries served:

  • Industrial
  • Government
  • Power generation providers (hydro, thermal, and nuclear sectors)
  • Private sector companies
  • Engineering consulting firms

ASI Hydro’s hydrographic mapping services provide clients with a thorough underwater investigation of the conditions of rivers, estuaries, channels, lakes, harbour bottom surfaces and submerged infrastructure.  A combination of geophysical mapping equipment and the latest charting technology enables us to locate and assess any submerged surface features and targets addressed by our clients.  The findings are measured and mapped with precision accuracy in real-time.

ASI’s underwater mapping services include:

Multi-beam Bathymetry

  • 100% bottom coverage
  • High precision bathymetric data
  • Ideal for large areas
  • Compensation for vessel pitch, roll and heave
  • Image mapping

Single-beam Bathymetry

  • Highly accurate water depth and bottom contours
  • Low cost
  • Highly portable enabling expedited mobilization
  • Easily deployed on small boats/ships

Side Scan Sonar

  • Industry standard technique for image mapping
  • Provides excellent target detection, bottom classification
  • Highly accurate
  • Used to delineate very small targets and bottom features
  • High or low resolution options

Sonar Profiling and Imaging Surveys

ASI Group provides a wide range of sonar technologies that enable data collection in high flow, highly turbid and hazardous environments.   ASI’s Dual-Axis Sonar (DAS) system technology enables collection of critical underwater infrastructure data without the burden of costly downtime.

Benefits of Sonar Surveys:

  • Remote target identification
  • Monitoring of silt and debris accumulation, scour and erosion in hazardous conditions
  • Observation of collapse or undercutting occurrences enabling corrective action
  • Remote measurement of infrastructure

Through our company DS Salvage we complement ASI Hydro services, supporting all activities that require commercial diving support.

Implemented Projects

Inspección Hidroeléctrica

 Colbun S.A.
 Canutillar, Chile
 5 días
 Inspección de Tunel de Aducción

Inspección Hidroeléctrica

Chiriquí, Panamá
7 días
Inspección de obra toma, chimenea de equilibrio y compuerta de descarga de fondo de la Presa.

Inspección Hidroeléctrica

Tinguiririca Energía S.A.
 San Fernando, Chile
 7 días
 Inspección de Tunel de Aducción

Inspección Hidroeléctrica

Colbun S.A.
Canutillar, Chile
5 días
Medición de Espesores de Tuberías Hidroeléctrica.

¿Need Our Services?

Fill the contact form or contact directly our Area Manager:

Alejandro Peña  / / +56 9 8501 0930