for info...
UK and Ireland, Masters and Mates Certificates, 1850-1927
John Parkin age 32 (1823) Birth Place: Hull, Yorkshire
Issue Date: 14 Apr 1855
Issue Port: Custom House Hull
Certificate Number: 79.257
Employed App. Seaman & mate 15 years in the British Merchant Service in the Coasting & Foreign Travel
John Parkin age 36 (1823) Birth Place: Hull, Yorkshire
Issue Date: 15 Jan 1859
Issue Port: Hull
Certificate Number: 19.759
Certificate states he’s duly qualified to fulfil the duties of Master in the Merchant Service and granted a Certificate of Competency
1901 census RG13; Piece: 3434; Folio: 106; Page: 21
John's occupation noted as a Retired Master Mariner
ADDED for info...
27 Sep 1873 St Barnabas, Liverpool, Lancashire, England
William Parkin 26, Mariner, 19 Flint St.
Sarah Ann Langley 23, 19 Flint St.
Father John Parkin, Mariner
Father Thomas Langley, Brewer
Witness: Samuel Oakley; Mary Ann Parkin
from Lancashire OPC
Liverpool, England, Crew Lists 1861-1919
William Parkin age 26 (1847) Birth Place: Hull
Event Date: 1873
Port of Registry: Liverpool, Lancashire, England
Ship Name: City of Brooklyn
Official Number: 58971
Reference Number: 387CRE/209
Duly qualified to fulfil duties of Second Mate in the Merchant Service
William Parkin age 26 (1847) Hull, Uk
Issue Date: 10 May 1873
Issue Port: Liverpool
Certificate Number: 18381
UK and Ireland, Masters and Mates Certificates, 1850-1927
William Parkin age 33 (1847) Birth Place: Hull
Issue Date: 16 Jun 1880
Issue Port: Liverpool
Certificate Number: 18381
Duly qualified to fulfil duties of Master in the Merchant Service