SS Cushag was a coastal cargo vessel owned and operated by the Isle of Man Steam Packet Company between 1920 and 1943.

Cushag was a steel; single-screw vessel which had a registered tonnage of 223 GRT.

Cushag had a single steam reciprocating engine which developed 350 i.h.p.

Her first owners were James Waterson & Co. of Antrim, who sold her to Humber Steam Coasters Ltd in 1914.

Five years later she was sold once more, this time to a London broker, from whom she was purchased by the Isle of Man Steam Packet Company in May 1920, at a cost of £22,000 (equivalent to £1,116,197)[1].