I've found a death entry for a
William WOODS age 56 (b1818) Jun q 1874 Cardiff - I wonder if this his him 
I doubt whether this is the William WOODS I'm looking for as I've found a
1851c transcript HO 107 / 2455 Cardiff, St. John
William Woods b1819 Colchester occ. PLUMBER (master) not MARINER married
to Ann Woods b1817
1871c transcript RG10/5357/F?
William Woods W 53 b1818 Plumer & Master Gt Essese Glamorganshire
5 Working Street Cardiff Glamorgan
I have however found these Wm. WOODS occ. MARINER which maybe worth me looking at as I've nothing else about Mary WOOD/S father to go on other that what was entered on her marriage certificate (Jan. 1880) that her father named as William WOODS (deceased) Mariner.
1851c transcripts
HO 107 / 1777
William WOODS mariner b1822 Essex (posted help Essex board)
HO 107 / 1880 East Stonehouse
William WOODS mariner aged 46 ? b1805 ...?bridge married Ann aged 25
RG9 /4036/~F65
William Woods 76 b1785 Retired Ship Master Yarmouth Norfolk
2 Landour Square American Hotel Cardiff Glamorgan
(He would be too old to be Mary's father but maybe g/f?)
