Apparently so, because there is indeed one north of the airstrip. You visit the place in some mission (can't remember the name right now - one where you follow a bunch of dropped packages?)
It was during one of the Torino missions, 'Interdiction', where you had to use the Rocket Launcher to take down the rival helicopters.
The Seasparrow is due north of the airstrip (go under the bridge, out to the water) and it sits off the right side of the dock.
Yeah, what he said, do you remember the mission where Torino has those speakers?
Tip: A broken down pickup truck usually spawns there.