I've done this dive lots of times, (never taken a "Police" or any other car with me, though).
I have to admit that the Officer acted well, in a panic situaltion ( after his driving, which was "Not Great" :confused: , he missed a stop sign, and several Dead End Signs)
The officer; who was admittedly, not a great swimmer; had the presence of mind, as his car was sinking, to toss his gun belt, and bulletproof vest, into the back seat of the car, before exiting the car, through the window.
Things can be replaced, but your life CANNOT!
Ditch anything heavy, and wait for the pressure to equalize, and open a window if you can... The seatbelt buckle makes a great "glass cracker" if you need it to get out!
As well as he did, I'm sure his next 200,000 radio transimissions, will be acknowledged with the phrase "Aye,Aye, Captain Nemo"