“The discovery of a submarine carrying 3,000 kg (3.3 tons) of cocaine off the coast of Spain marks a “historic” turning point in the battle against drug trafficking, Spanish authorities said on Wednesday.”
That looks like an awful long way for a Self Propelled Semi-Submersible (SPSS), about 4,000 nautical miles. Have to wonder if the goods were not shipped first to Africa and perhaps the SPSS was built there? Alternately could the SPSS have been transported part of the way by a larger vessel?
Chuck Hill's CG Blog 
I think it was towed a good way. But I too thought it sounded ‘odd’.
The person to speak with about such matters is Mr Sutton with his Covert Shores site.
http://www.hisutton.com/
I checked Mr Sutton’s Covert Shores blog, which is on my recommended blogs list that day, but so far no mention of it. He will probably address it later.
H. I. Sutton’s analysis. Comparison with an earlier SPSS captured in the Eastern Pacific that shares some characteristics.
https://www.forbes.com/sites/hisutton/2019/11/27/new-drug-submarine-captured-in-spain-may-be-connected-to-pacific-example/?fbclid=IwAR2l_LBxtiOz-eXOr4xcoGIc-3VInHl_dyBtVWj_s5wkeW5_vty5vS1XNGY#715c05742453
I imagine the crew members of that semi submersible are getting the inquisition treatment at the hands of the Spaniards now.
Some more info including photos here: https://www.thedrive.com/the-war-zone/31248/the-first-narco-submarine-ever-seized-off-a-european-coast-is-a-monster
The vessel was about twice the size of the typical SPSS the CG normally encounters.
I ask a couple of friends about this and the thought a single hop would be possible based on what they have seen recreational vessels do. The authorities have the ship in custody and they have the number of days underway, displacement and fuel capacity – so given that it would seem to me a good marine architect or engineer should be able to get an approximate range of travel – since they have been building these ships for several years the designers should have fuel usage numbers –
Hopefully, even if we don’t see such a determination, the intel will be passed along to those who need it.
Drug smuggling to Europe by other means. https://gcaptain.com/europe-flooded-with-cocaine-despite-coronavirus-trade-disruptions/