Hi Barry , Frances has the right Robert , he did arrive on the "Adam Lodge" the information is on the NSW State Archives , he is aged 24 and single, Parents Thomas and Margaret , he is from the Isle of Man.He is shown as a farm labourer with in brackets " Cook on Board"
However the 1841 marriage you mentioned is for Robert Lucas ?? How do you know they are the same ?
On Trove , the newspaper "Empire" dated 17/3/1851 a story about the loss of the brig "Gazelle" with all hands on the 25/11/1850 on way to London , Robert Lucas is shown as a steward.
There is a death of Robert Clucas in 1857 aged 48 , no parents .
Are they two different people ?

Cheers
David Dwyer
Sydney