It does not make sense. There are thousands of boats in the ocean that don't draw attention but one sub will capture the attention of the US Navy.
But, you got to hand it to these guys they are very creative.
They are creative!
Might not be drugs. There are alot of camel jockeys with extra pocket change right now. Drugs would be a good cover. 200 tonnes is quite a bit of WMD cargo capacity. Since they were surprised by what they found, it might have had a chance to get one run. How many more are building?