Great Grandfather's Naval Service

A Memory of Devonport.

My great-grandfather John King served as an AB on HMS 'Royal Adelaide' from 11th August 1867 to 12th May 1868. His service record was marked 'Shore C S expired'. He joined the navy in 1856 aged 15 years and 9 months. This marked the end of his first term of 10 years as an adult in the service. He was from Kilrush, Co. Clare in Ireland and and I have a record of his marriage on September 14th 1867 in St Senan's R C Church in Kilrush. The marriage record states he was a seaman on board HMS Liverpool but his navy record shows he was discharged from the Liverpool on 10 August then joined the 'Royal Adelaide' on the 11th August. Upon his discharge from the 'Adelaide' his record shows the only break in service over his career spanning 34 years as he then joined HMS 'Frederick William' on 2nd July 1868. I am puzzled by the discrepancy in the dates but I wonder if his service on the 'Royal Adelaide' included some leave due as his 10 year engagement was almost served and he was able to travel back to Kilrush for his marriage.