The Robert Corlett, mariner at his 1872 marriage, appears to have had a change of occupation if this is the same person in the 1851 census. At marriage he was recorded as Mariner, Kerroo Muir, Lez., with his father as Thomas Corlett, Labourer.
The closest Robert I could find in the 1851 Lezayre census was in Kerroomoar, 19, shoemaker appr., with his parents Thomas 53 farm labourer, Jane 47, and 4 siblings, all b.Lezayre.

Possibly Thomas CORLETT & Jane CAINE married 1 Dec.1827 Lezayre.

Sue