the ship " came from something I found on the web, I am now wondering if it was Navrra of Rotherhithe?.
Never take anything from the net as truth. People make mistakes, typos, etc. I have found over the years that it pays to consult as many references as possible to double or triple check, using original sources where ever possible.
I am 99/% sure that the name "Navrra Rotherhithe" is erroneous and a vessel with that name did not exist.
According to the 1891 census, William was in Goole on the night the census was taken. As he was a coastal sailor who could be at home on a regular basis, this may not be entirely true.
He has no records in Lloyds Captains register because he only held a Home Trade Certificate.
DENBY, William born. Wisbeach 1855 HTC 102298 passed Hull 1885
If his records are anywhere they will be in the British National Archive.
http://discovery.nationalarchives.gov.uk/SearchUI/Details?uri=C408339I understand there are records on Ancestry.com but I do not know if they cover HTC. Maybe worth a look.
If there are no records available from these two sources, then you would have to backtrack via the vessels crew agreements. But let's wait and see what you find before setting out on that course.