We were told that the Dearls had lived in Clontarf, Dublin for many generations, and there was a Sea Captain in their ancestry.  Further research discovered not one but several seafarers - going back to one William Dearl who was the purser of His Majesty's Frigate 'Fox' according to his will, proved in 1814.

But though several generations certainly did live in Clontarf, the DEARL line seems to have originated not in Ireland at all, but in Hampshire - and several generations of Dearls lived in Chatham, Kent.  I have also discovered a whole new branch of DEARL(E)s who lived in the East End of London ... and there may be a connection to John Henry Dearle (1859-1932) who became Chief Designer to William Morris (see Wikipedia article).  This needs further checking.

It has also been fascinating to discover more about the family in Clontarf (thanks to the release of so many useful Irish records and all the help gratefully received from Alan and Karen).