Diving Company in Porsgrunn, Brevik and Langesund – UWILD and Hull Inspection
Kristiansand Bygg AS is a DNV-approved commercial diving and ROV contractor serving vessels and port facilities in the Grenland ports: Porsgrunn and Herøya, Brevik and Stathelle, and Langesund. We carry out in-water surveys for class, hull cleaning, propeller polishing and underwater repairs afloat, with our own divers and our own PIVOT ROV.
For captains, superintendents and ship agents this means one contractor for the inspection and, in many cases, for follow-up work found during it, without moving the vessel to a drydock.
DNV-approved in-water survey (UWILD / IWS)
We hold DNV Approval of Service Suppliers under DNV-CP-0628 (certificate AOSS0000S13, valid until 2029). We carry out Underwater Inspection in Lieu of Drydocking (UWILD), also known as In-Water Survey (IWS), for class in the Grenland ports. The exact inspection scope is agreed directly with your vessel's class surveyor.
The survey is carried out by diver or by ROV, depending on the scope and conditions, with diving and inspection to 50 m. We can provide a live two-way video feed so the class surveyor can follow the inspection remotely in real time.
- Hull plating, propellers and rudders
- Thrusters, sea chests and other underwater openings
- Cathodic protection (anode) inspection
- Reporting with video and still images for owners, managers and class
Read more about our underwater inspections in Norway.
Hull cleaning and propeller polishing
Fouling on the hull and propeller increases fuel consumption. We choose the least aggressive cleaning method that will effectively remove the fouling, adapted to the antifouling coating and the type of marine growth. Hull cleaning is carried out subject to port and environmental requirements.
- Flat bottom, vertical sides and rudder
- Sea chest grids and niche areas such as bilge keels
- Propeller polishing to remove barnacles, tubeworms and calcareous deposits
Underwater repairs afloat
When the inspection finds damage, our divers can often repair it in the same visit. Our team consists of craftsmen who dive, not divers doing craft.
- Thruster and sea chest cleaning and repairs
- Inspection and repair of underwater openings (sea chests, thrusters, valves)
- Welded crack repairs and rudder repairs
- In-water propeller repairs
- Anode inspection and replacement
See the full list on our underwater services page.
Ports we cover in Grenland
- Porsgrunn and Herøya
- Brevik and Stathelle
- Langesund
We work at quays and industrial berths throughout the Grenland area.
Also serving the Stavanger area
Mobilisation from Kristiansand and Flekkefjord
Our mobile diving stations can be dispatched within the hour from our bases in Kristiansand and Flekkefjord, and we reach the Grenland ports along the E18. For urgent jobs, call us directly on +47 902 03 797.
Local track record
In 2025 we carried out a complete quay demolition for Eramet in Porsgrunn, from planning and securing the site to full removal of the structure. Concrete elements were cut with vibration-free wire sawing, and heavy masses were lifted directly from the water with our work vessel Dykkeservice 5 and its 32 tonne-metre (tm) crane. The vessel lets us work independently of land-based cranes at industrial quays.
PBCF installation for Gearbulk
For the shipowner Gearbulk we have carried out inspection and installation of PBCF (Propeller Boss Cap Fins) on M/V Misago Arrow (IMO 9448243), a general cargo vessel. The job was carried out in the Grenland area, and the work on the propeller and boss cap was done in the water, without drydocking.
Frequently asked questions
Can you carry out a UWILD or in-water survey in Brevik or Porsgrunn?
Yes. We carry out UWILD / In-Water Surveys for class in Porsgrunn, Herøya, Brevik, Stathelle and Langesund. We are DNV-approved under DNV-CP-0628 (certificate AOSS0000S13), and we agree the exact scope directly with your vessel's class surveyor.
What does an in-water survey or hull cleaning cost?
The cost depends on the vessel size, the scope of work, visibility and depth, and whether a diver or the ROV is the best method. Send us the vessel details and the scope, and we will give you a quote.
How quickly can you reach a vessel in Porsgrunn, Brevik or Langesund?
Our mobile diving stations can be dispatched within the hour from our bases in Kristiansand and Flekkefjord, and we reach the Grenland ports along the E18. Call +47 902 03 797 for urgent jobs.
Can the class surveyor attend the inspection remotely?
Yes. We can provide a live two-way video feed so your class surveyor can follow the inspection remotely in real time.
Do you use divers or an ROV?
Both. Most inspections and repairs are done by our commercial divers (Kristiansand Bygg AS is DNV-approved under DNV-CP-0628), with diving and inspection to 50 m. Where a diver is not needed or access is difficult, we use our own PIVOT ROV with a manipulator arm, a 300 m tether and surface-supplied power from our own generator.
Are you a DNV-approved diving contractor?
Yes. Kristiansand Bygg AS holds DNV Approval of Service Suppliers under DNV-CP-0628, certificate AOSS0000S13, valid until 2029.
What we need from you
When you contact us about a job, please include the following:
- Vessel name and IMO number
- Port and berth or quay
- ETA and ETD
- Draught
- Scope of work: inspection, cleaning, repair, and any class requirement
- Class society and surveyor contact, if a class survey is involved
Send the details through our contact form or by email to epost@kristiansandbygg.no.
Request an in-water survey in Grenland
Send us the vessel name, port, dates and the scope you need, and we will get back to you.
Phone: +47 902 03 797
Email: epost@kristiansandbygg.no
Contact form
Related: Underwater services · Underwater inspections · ROV and diving services · Dykkerfirma Grenland (norsk)