I don't know a lot about boats, but I have developed quite a fondness for old paintings of them, and I really love the warmth and folkiness of this one. The single funnel steam ship itself fairly closely resembles the CSS Acadia, built in England during the first decade of the 20th century, and used to survey Canada's northern waters. I am not sure this boat is that, but do think it is likely earlyish 20th century British, and believe the blue flag with red cross may be a British naval flag.
The painting I'd think dates sometime between the 1910s and early 1940s. I really like its combination of specific details and loose gestures, with these precision of the masts contrasting with the painterly waves, clouds, and especially that kind of messy trail of black smoke. Very sweet.
Oil on cardboard and kind of shiny. The cardboard I believe was not too long ago glued to a piece of foam core to stabilize it, so it is impossible to know if it was signed on the back. It shows some age: there is a tear near the center of the water, running to the bottom edge, and a couple of scratches near top center of the sky (see detail photos)--neither particularly visible when inside the frame. Sold as I found it in a gilded wood frame, which is in good condition (I have taped around the edges on the back to prevent it from sliding around a bit in the frame). 11" x 15" x 1".
Note: photo of painting frame shows glare.