Stupidity: Coffey uses the submersible "Big Geek" to carry the armed nuclear bomb to the NTIs. If Coffey was that desperate to blow up the aliens, he could have much more easily set the timer for 30 minutes, driven one of the submersibles far out over the abyss past the drop-off, and simply dropped the bomb down and let it sink under its own weight.
Watcher1
26th Dec 2013