It's not like Columbian smugglers ever dumped cocaine cargo in sea to evade capture.
That reminds me coffee smuggling here. Back in the times of Yugoslavia, there was a hefty import tariff on coffee (and other stuff) so you could make a good profit by getting coffee past customs unnoticed, practically a national sport for Slovenia in those days. But there is only so much coffee you can hide in your car and customs guys knew where those places are, so smuggling through border passes was a lottery.
Then one guy came up with an idea how to smuggle coffee in quantity, past the customs and border guards. You could buy coffee in big waterproof sacks, but that one is rather difficult to hide. They are buoyant enough to float on water surface, but if you tape a sack of salt to it, it will sink just deep enough not to be seen on the surface and be carried with water current, salt gradually melting away so the sack comes to the surface eventually and can be picked up. So they did this on the Drava river, tossing the taped together sacks into river on the Austrian side, on the point where border guards couldn't see them and they had to fish them out before Dravograd hydro power plant, there was a fishing spot that served as cover for this.
Eventually they lost one of the sacks and police realised someone is using river for smuggling, but they still carried on and got caught, apparently through very enthusiastic application of beatings. Such smuggling is now thing of past, but Drava river coffee smuggling is part of local folklore, with tales and songs memorising it.