DOF Group chief executive Mons Aase has said it is still very tough to secure decent platform supply vessel (PSV) rates in "dark" days for the sector.

The Norwegian company had 13 vessels laid up in weak markets at the end of the third quarter, about half of these being older PSVs.

Speaking on an earnings webcast, Aase said the outlook for offshore ships is still poor, with global PSV markets in particular "really tough."