Siem Offshore Inc. has declared an option for the construction of two additional large VS 491 CD AHTS at Kleven Verft AS.

Following this order of two AHTS, the Company has 12 similar AHTS under construction.

The vessels which are of Vik-Sandvik VS 491 CD design will have 28,000 BHP, a bollard pull of 300 tons, winch of 500 tons, accommodation for 60 persons, full PSV capacities and are designed with special focus on safe anchor handling operations.

The vessels will be delivered in October and December2010.