Originally Posted by Anno_Domini
When the guy who names a vehicle The Bat mentions submarine
instead of a bat, why would I not suspect Bruce would use submarine as well?
Timing. In DKR Bruce had already retired from being Batman--
"These conversations used to end in an unusual request."
"Let's have a look anyway."
He and Alfred are trying to get him engaged in living his life again through their own ends of the spectrum--in Lucius' case fancy toys with a less-than-subtle namedrop.
In TDK, they're still operating under "If you don't want to tell me what you're doing, if I'm asked I don't have to lie" mentality. Him finishing Bruce's sentence with submarine is essentially saying "I don't want to know."