I did transport a canoe a few times on my Contour GL (I guess not much different from an SVT at this).
The canoe rental place gave me a "canoe car-top carrier kit" which is basically 2 pairs of slabs of plastic foam (cca. 4x4x4 inch cube with a slit) to pad where the canoes rim touches the roof, and some ropes to tie down the front and rear and also across the side through the open windows. The canoe is upside down of course.
It worked unexpectedly well, I did 60-65mph without any trouble, above that the ropes started to sing very laud

First time I made a bad mistake though, I didn't position the slabs carefully enough (i.e. be aware of the dome shape of the roof) and scratched the roof paint real bad with a screw head protruding from the canoe's rim.
Tiv