Worms Armageddon | Swimming Missile
Well, I didn't discover America with this one, but I believe there are still players, who do not know about this possibility.
Do not fire the missile too fast, as it sinks if:
it do not start homing before reaching the bottom of your screen,
it dives too deep into the water while homing.
Enjoy!
Soustruh - http://wormscesky.cz