Hampton Creer "Never to Return" has him aged 11 convicted along with 2 other boys to grand larcency of a rope off a Whitehaven vessel called the Stag in Nov 1836 and transported to NSW on the James Pattison on 5 Jul 1837.

Can't find an obvious baptism - Briggs is a non-Manx name and tho there are a few in baptismal reg none match - possibly try www.iMuseum.im to see if newspapers have more details re parentage