Hi there Hitman. Just a quick question. Have you downloaded the Dangerous Waters demo? It has one mission where you get to try out the Kilo with working snorkel and every thing. If you have not then it's worth a try just to see what it's like. I to enjoy driving a diesel.... Follow this link for the download if you want to check it out.
http://www.battlefront.com/products/dw/demo.html
If you've already tried it out, sorry for the waste of time.