It's a pipe-burying vessel. She has holds for bulk (like stones or similar) & conveyor unloading system that via the hanging pipe, lowered on a certain depth, pours those stones on an already laid cable/pipe by cable/pipe-laying vessel.
I'd suggest to place these pipe burying vessels either in Bulkers or Special Purpose Ships.

Bulk carrier converted for pipe-laying

The Equasis data updated as at 16/12/2015 is

IMO number : 8315554
Name of ship : TERTNES (during 1985)
Call Sign : C6AS8
MMSI : 311000142
Gross tonnage : 7857 (since 01/07/1998)
DWT : 11546
Type of ship : Pipe Burying Vessel (during 1992)
Year of build : 1985
Flag : Bahamas (since 01/01/2015)
Status of ship : In Service/Commission (since 20/01/2000)
Last update : 16/12/2015

Great photo - super angle. I note with interest the Photo Category.