Please avoid being in this river. For one thing, it’s December in North America and you’re a mammal. For another, your submarine is backordered and prone to grounding in the shallow spots. Years ago, the river used to freeze solid and we joked that between semesters, math professors would throw themselves off this bridge and get stuck in the mud instead of drowning. After the county dredged a few times, nobody makes that joke anymore. We just hope math professors pre-ordered their submarines.