HMS St Vincent was a 120 gun Ship of the Line launched in 1815 but not commissioned until 1829, she saw mixed service until becoming a training ship in 1862 and being permanently moored at Haslar in 1870,. She was decommissioned in 1905 and sold for scrap in 1906.
The date on the photo shows 1910 but this is four years after she was broken up in Falmouth in 1906.
Photographer unknown