There is a pond I am going fishing on with a buddy. I've been there a couple of times and he has been there a lot. We have no idea of the depth and what structure is below. How can I set something portable up so I can take the one off my boat and put it on his bass buster?

just get a portable fish finder. it has a suction cup on the transducer to stick on the boat. or buy a cheap graph and mount one on the boat. i bought 2 garmin 240 for 80 bucks a piece

humninbird make a smart cast depth finder. its pretty dang kool. i used one when i'm fishing ponds from the bank (my wife got me this few hrs back). depth finder is 2 section watch band with monochrom monitor and bobber with a sensor telling the depth and sometime a fish. its small and very portable and easy to used check it out. here's a link.
http://www.basspro.com/webapp/wcs/stores...0003000_250-3-0

but if want a big screen Lowrance make a portable depthfinder that runs on batteies, but its little big then a watch style, what i stated above. go to basspro shop and they a demo model on there shelf. here a link to this http://www.antarespro.com/2811362-item-L...318d309d313d316

Just sound it the old fashioned way with a T rig or a Jig.

To move yours you would have to have power cables and a transducer. More than likely you'd be out over $100. I think you could get a cheap one or a good used one for the same or less and not have the bother of changing back and forth.

come to think of it I have a transducer that goes on a trolling motor that isnt being used, may have an extra power cable. Could I just cut the ends of the cable and add connectors for a battery?

If it is the same as the one you your unit there should be no problem as long as you fuse it.

How would I go about that?

What about a fishin' buddy from humminbird? Has anyone ever used one of those?