Abstract: An unbonded flexible pipe with a length and bore and an offshore installation are disclosed. The pipe comprises an internal pressure sheath, at least one metallic armouring layer surrounding the internal pressure sheath and at least one additional layer surrounding the metallic armouring layer. The metallic armouring layer comprises helically wound armouring elements which are at least partly covered by a viscous fluid having a kinematic viscosity of at least about 1000 cSt (ASTM D445 or ASTM D2170). The at least one additional layer surrounding the metallic armouring layer provides a gas escape route radially outwards from the metallic armouring layer beyond an outermost layer of the least one additional layer or to a lengthwise gas escape path in or between the at least one additional layer.