A pipe-in-pipe (PIP) connector for use in a PIP pipeline for laying in a marine environment, the PIP pipeline including at least metal inner and outer pipes and an annular space thereinbetween, the connector including at least: (a) a first connector end including inner and outer longitudinal collars corresponding in circumference to the circumferences of the inner and outer pipes of the PIP pipeline, and weldable to a PIP pipeline, and (b) a second connector end including a machined portion configured to match and connect with a complementary portal or bore of an in-line subsea structure, and a coupling portion for coupling with a pipeline section, the coupling being decoupable.