no ingame pics sorry but it works as long as you have the water camera mod. the butterknife class is one of 3 classes of submarines in the croftien democracy and is the only nuclear one. the butterknife class is capable of delivering a medium range nuclear warhead at your door for 1200 miles away and at a launch depth of 150 ft but can go as far as 4900 ft down and stay submerged for 95 years if you had enough food.
stats:
engine?: aircroft industry HKL200 uranium reactor
power: god knows
top speed: 76mph
max depth: 4900ft
price: £1.2 billion
controls: trim for deph control yaw for turning (it isnt very good sorry)
notes: dont pitch up too much as it may flip requires underwater camera mod to work red bit will detach automatically