These were made in Germany by Lehmann from 1914-38 and were designated as EPL 672. It is a large (13 inch) windup floor toy with two smokestacks and two masts.
It has rotating guns and removable lifeboats that pivot and draw down. Flags originally adorned each end of the boat and on each mast . It runs in circles and stops when you lift it off the surface (“automatic arrest”).
The real St. Vincent was a war ship engaged in the Indian Ocean over trade wars.