Transducer wire holders to keep my transducer wire tight against my transom.

Home depot or Lowes. Or West Marine or any hardware store or from me.

I tried Lowes in Little Elm and they did not have them.
I need to bring my boat by to show it to you when you have some free time.

You looked in the telephone or cable sections?

radio shack

The correct name for what you need is "cable clamps". As other posts say, Home Depot, Lowes, Radio Shack and any other electronics or hardware store will have some variety of cable clamp. They come in lots of styles. I like the self adhesive type because you do not have to drill holes in the boat. Look at this on-line ad for a few of the types.

ace hardware has them also

Thanks everyone.