This one is easy... are you using the sled for it's intend purpose? Same as riding double when the machine is NOT made to ride double. If you miscalculate and the sled sinks...will it become a hazard, foul the water?? You can get a ticket alright.
There is also a law that prevents crossing navigable streams by ATV or sled. If you get caught you get a ticket. It errodes the stream banks....Never mind that it also puts the sport in a bad light.
When in doubt...don't do it.