Columbia claims to have found their first fully submersible narco submarine. Looking at the pictures and the specs given, its apparent that this is a different sort of craft. The claimed maximum dive depth is only three meters (10′) and there is what appears to be a permanently fixed snorkel 5 meters (16.5′) in length, meaning, even when at maximum depth, the top of the snorkel will be above the surface. Unlike the true submarine found in Ecuador, there is no mention of an electric motor. It’s not really a true submersible, but it’s not a typical semi-submersible either. It seems this craft is intended for “SNOrkel Transit” so my shorthand description would be that it is a “Snot boat.”
A snorkel (or snort), basically a pair of hoses, one bringing in fresh air and the other taking exhaust gases to the surface, allows the sub to run submerged on diesel. On a conventional submarine, it not only propels the submarine, it also allows the batteries to be charged while submerged.
Snorkel transits can be very unpleasant. The intake and exhaust are close together. If the wind is blowing the wrong direction, exhaust gases enter the intake. If the seas are not calm, waves may wash over the top of the snorkel. A float valve temporarily closes the intake to keep the engines from ingesting sea water. When this happens the diesel gets its intake air from inside the submarine resulting in a sudden and unpleasant drop in ambient air pressure that effects the ears and sinuses.
The photo below shows an electro-optic device mounted on the top of the snorkel. Presumably there are radio and GPS antenna as well.
I would expect this vessel to transit in company with one or more fishing boats that would act as scout(s).