IMO 9407990 , Call Signal LAKL , Flag Norway.
Class : Det Norske Veritas.
Ship Type : Multi Purpose Offshore Vessel.
Build in 2009 by Maritim - Shipyard Spolka Zo.o Gdansk Poland / Complited by Havyard Lairvik i Sogn Norway as " HAVILA PHOENIX " for Owner / Manager Havila Shipping A/S Fosnavåg Norway.
Tonnage : grt / nrt / tdw - 9.418 / 2.825 / 6.250.
Main Generators : Caterpillar 3516B - 6 x 1.300 kw.
Aux.Engine : Caterpillar C9 - 1 x kw.
Propulsion : Diesel Electric Rolls-Royce Azimuth - 2 x AZP 120 CP.
Dave, I think it is classed as a Subsea Construction Vessel. The grey tower sitting behind the accomodation block is used for subsea well intervention, whatever that means. The large opening on the side will be where the ROV unit is launched subsea.