Ohhh pipe not plumbing pipe

The cannabis plant when left to itself doesn't create much THC (which is what gets you high), but it is very useful for making rope and clothing, as well as oil and other products. Only when you make sure that you only have female plants (and take care of them in a certain way) do they produce lots of THC.

So just because the plant is growing somewhere doesn't mean that someone is smoking it.

The active drug part of the plant is the resin found at the flowers of the female hemp plant, created during pollination season. There is neglible amounts of THC in the rest of the plant, as in basically nothing. So you would only get high if you smoked that particular part of the plant, not the rest. So sailors could have saved on tobacco by using the dried leaves of the harvested hemp plants they imported for rope, but it wouldn't have made them stoned in the slightest.

To add, hemp was farmed for it's fibers, to make rope and fabric

Sorry, I read it as plumbing pipe for some reason.