Ulstein has been awarded a ship design contract from Vroon Offshore Services, taking the total number of offshore ship designs it has sold in 14 years to more than 100.
Of the designs sold, 74 were for Ulstein's X–BOW design, launched in 2005.
In total, 25 different ship owners have ordered Ulstein designs, with 16 different shipyards building the vessels.
Of the 100, 62 have been built at yards worldwide, with the remaining 38 built at Ulstein's own yard, Ulstein Verft, on the west coast of Norway.
The latest contract for two PX121 PSVs (ship numbers 100 and 101) will be constructed at COSCO (Guangdong) shipyard in China.
The vessels will be used in European waters.
Ulstein's offshore ship designs were introduced in 1999. The first of the new generation, the multifunctional anchor handling vessel (AHTS) Olympic Hercules, was delivered in 2002.
In 2005, Ulstein marked the launch of the X–BOW, first seen on the AHTS Bourbon Orca. The design aims to reduce movements and eliminate wave slamming and bow impact, stabilising the work platform and improving comfort for crew.