Supervision of Nearshore Outfalls on the Island of Krk (ROV)

Survey and documentation of 7km of nearshore outfalls and marine gravity drains within the public drainage system on the island of Krk

The island of Krk has a responsibility to ensure that its nearshore outfalls are functioning properly and are not causing any harm to the surrounding environment.

To achieve this, a visual inspection was conducted using remotely operated vehicles (ROVs).

By using ROVs, inspectors can obtain a visual inspection of all visible damage and problems in function from the safety of a control room.

This eliminates the need for divers to physically inspect the outfalls, which can be dangerous or even impossible in some cases.

Additionally, ROVs are equipped with high-quality cameras and lighting systems, which provide clear and detailed images of the outfalls.

Ensuring Proper Functioning of Nearshore Outfalls

The results of this inspection will be crucial in determining the current state of the nearshore outfalls and identifying any necessary repairs or improvements.

During this project, we used a remotely operated underwater vehicle (ROV) equipped with high-resolution cameras and an underwater GPS system.

This was our first use of digital anchor technology (positioning the vessel above the outfall) and the SfM (Structure from Motion) method to better detect the state of nearshore outfalls.

The choice of a ROV that can turn on its x, y, and z axis proved to be critical; as nearshore outfalls are often used as anchor points for buoys, avoiding anchoring ropes during automated inspections became an imperative.

The project included:

  • Mapping the sea floor with lateral sonar mounted on a remotely operated underwater vehicle (ROV)
  • Programming inspection routes by ROV
  • Examination of nearshore outfalls using a ROV equipped with at least four high-resolution cameras and an underwater GPS device
  • Validating data using standard statistical methods
  • Drafting a report on the current state based on visual methods, including the creation of a 3D model of the sea floor and outfalls at each location, as well as defining specific damage using photogrammetric methods

You can see an example of what our 3D models of submarine outlets look like on our official video channel.

For more information, “Outfall Photogrammetry Rovinj (ROV)” is one of the many reference underwater outfall recording projects.