Smugglers have used submarines. Law enforcement has already "no hope", and that is entirely by design. If you want LE and criminals to be equal then you end up in a country run by criminals.
No, there is more than the technical advantage held by police which factors into this. There is also the extent to which the mass of people tend to believe whether it is better to do things in a law-abiding manner or whether legal authority is completely disrespectable and not worth obeying.