Can Submarines Help Enforce Immigration Laws?

Looks like USS San Juan (SSN 751) had an interesting port egress from Gibraltar this week:

Four Moroccans hoping to make an illicit crossing to Spain to join thousands of illegal migrants there suddenly found themselves alongside a US nuclear submarine, reports said Sunday. Crew of the 110-metre-long USS San Juan discovered the Moroccans' flimsy boat bobbing at their side as the huge sub was easing out of Gibraltar, El Pais newspaper said.
The US crew informed Spanish coastguards via the submarine's base in distant Norfolk, Virginia, and a Spanish rescue boat was sent. However, a Moroccan patrol boat arrived first - and repatriated the would-be migrants.

That's probably one of those things you don't cover during the piloting brief for leaving port -- "OK, and if we see a refugee boat, we'll prepare to repel boarders and contact Spanish authorities on Channel 17; if that doesn't work, we'll call up SubLant and let them deal with it."

I'm wondering if the people whining about the San Juan's visit earlier in the week were happy that they were available to help enforce local immigration laws? Probably not...