How do you do this?  Do you need a very sensitive depth finder?  It has never worked for me.

Seems like you would need an underwater camera for that?  I never seen a depth-finder record motion.

I watch my drop shot, shakey head, spoon, etc... all the time on my 525. I've watched fish race up, or dart to the bait, but I've never actually got to see one take it. I basically leave my settings to Auto (execpt depth) 90% of the time, I only mess with my sensitivity and colorline settings if I'm in really shallow or really weedy areas.

I think most any of today's sonar's are capable of doing this, its just a matter of having them properly set up.

I agree with dick. I leave mine on auto and once I get over the fish I am going to drop shot or spoon I zoom in. I am using an x135 and as long as I drop my bait next to the transducer I can watch it the whole way down. When you get around an active school you can watch the fish go down or up to get your bait. It is one of the coolest things I have seen.

You want to watch Jason Quinn do this in 50 foot of water on one of the BPS videos.  He was using spoons.  Man it was freakin awesome.

i would love to do something like that. Deepest water i have fished in the last few months is 6 feet. haha.