They are not submarines as generally understood even as far back as WWI. If they were our Coast Guard couldn't capture them with two small boats. Our local Coasties just returned from a deployment to the Pacific where they did just that.
WWG1WGA
Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)
Calling these drug transport vessels submarines is being far too kind.
I wonder if the Coasties have their screw signatures? Betcha they do. Just drive right to them and open the hatch.