When I canoe fished I carried an anchor that had been poured in a peanut can a long time ago. About 3” across and 2 1/2” tall on a quarter inch braided line. I’ve dropped it into some grabby stuff and always gotten it back. An anchor with a conical design would also work. I don’t have a weight on it but it’s not super heavy and always held. I did want a trolley though, that idea has merit.