Re shipping – my father-in-law helped set up the random testing for oil tankers. It’s expensive to helicopter out a testing kit but much cheaper than another Exxon Valdez.
1) The kits are kept on board, I'm pretty sure helicopters don't fly into the middle of the ocean.
2) Alcohol had no part to play in the Exxon Valdez, that's a myth that was started to scapegoat the captain (who never crashed it in the first place).
I think for safety critical folk like some of those mentioned random drug testing is acceptable - tho one issue is cannabis is detectable long after its ceased to have an effect. This is a tricky issue to deal with but I think and hope as the law matures on this that the limits will reflect this. Even passive cannabis smoking can show up in testing.
As for other folk in non safety critical areas - what they do in their own time so long as it does not effect performance at work is non of their employers business
If we drug tested every worker in the UK 10% of them would fail would be my guess quite possibly more given that drug use particularly cannabis is so widespread
