“Head out to that point. If you're going underwater to look at that big bad Russian submarine, you'll need to protect yourselves... with torpedoes. That's easy enough, but... torpedoes need ECUs, which you can't get in this country. Luckily there are some arms dealers on a platform just over the maritime boundary, who uhh... might have some in stock... so go do your, uhh... duty free shopping.”
— Lester's briefing.
The crew is instructed to go to a designated location, where Lester tells that they need torpedoes as a mean of defense against the submarine, but they need ECUs that must be stolen from arms dealers. These arms dealers are operating on a barge off the coast.
The crew then heads to the location, where one or two Seasharks may be provided as transportation from the marked point to the barge. The barge is guarded by various enemies on it, as well as two enemies on Seasharks.
Once they clear out the platform and takes the two duffel bags containing the ECUs, the crew have to deliver them to the Facility. Two enemy Froggers may spawn in an attempt to take out the crew, so the crew have to either evade them or destroy the helicopters.