With 20-year experience in the offshore wind market, we have developed our 10 FOB SWATH semi-submersible vessels (SWATH: Small Waterline Area Twin Hull). Our goal is to have the best personnel and vessels, using our experience and vessels to provide reliable services. Approved by DOCISO 9001, 14001, 45001, Achilles, Environmental Policies, GDPR, Danish Authority and DNV.


The 2 lower hulls are built for stability and speed. The pitching, rolling, and slamming are reduced due to the vessels design with ample distance from seawater to water deck. In rough sea and in semi submerged mode the vessels movements are significantly reduced. Our vessels which are equipped with exceptionally large water jets each supplying three thousand liters of water per second, is a great improvement while the vessels manoeuvre to the turbines, as well as using vessel’s automatic moveable foils.


Our special patented bow fender with moveable clamps used on the outside of the turbines docking poles keeps the vessels secured in the correct position and allows service personnel to use the “landings” in up to 2 m Hs.


  1. Fob Swath (FS) vessels have the following speed: FS 1 = 18 knots, FS 2, 3, 4, 5, 6 & 7 = 22 knots, FS 8 = 27 knots, FS 9 & 10 = 35 knots and if one propulsion unit should fail, these vessels continue with 25 knots.
  2. Sailing same distance, fuel consumption for our 32.5 m vessels at 33 knots are similar as our 25 m vessels at 22 knots. They can be powered with HVO(B100) or GTL fuels, reducing CO2 emissions up to 90 %.
  3. Our vessels with a length of 32.5 m have all Dynamic Positioning (DP), used among others while giving fuel and electricity for work carried out on the turbine’s platform.
  4. Acceleration in accordance with the High-Speed Code 2000, with vertical acceleration under 1 G, lowest sea sickness index at 0.75 to 1.25, comfortable and safe seating and sound level below 60 decibels.
  5. Improved performance and extra bunker capacity, provides additional working days.
  6. Free deck space up to 75 m².
  7. Some of our vessels can carry up to 55 Industrial Persons (IP). Alternatively, we can build accomodation vessels for 12 IP each with single cabin including WC., shower, etc. and in additional for 10 IP for day sailing.
  8. Change from CAT to SWATH mode or vice versa takes about 2 minutes.
  9. If one of our vessels need service, one of our available vessels can take its place.
  10. Our vessels have hydraulic operated rescue net, which ensures the rescue of persons with one deckman.
  11. FS 8, 9 and 10 have hydraulic operated gangway and all our vessels have cargo crane.
  12. In our workshop, we have considerable spare parts and complete engines and gears.

Offshore Windservice A/S.
+45 978 880 00

Nordsökaj 51, 7680 Thyborön, Denmark

Billy T. Kristensen +45 50 800479



Associated companies: Odfjell Eiendom AS, Bergen, Norway, has long term investments in real estate with over 135 000 m² of commercial properties, part owners in custom built vessels for Bahamas, ice classed vessels for the Baltic Sea and special vessels for the wind industry.

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