On my 12 year old boat, the cables and wires from the console to the motor are wrapped with a type of plastic about one inch wide and 1/16" thick. It makes a nice looking wrap.

Do you know what it is and where I can buy some?

I would assume it is split loom tubing, you can buy it at most automotive parts stores or try an auto salvage yard.  

http://www.wiringproducts.com/index1.html

The Big Box hardware stores carry it also.  Just go to the Electrical section.

Hydraulic and Hose shops offer a product like you want, they wrap hoses with it to cut down on abrasion's. just measure the diameter of your bundle. The type I get is black in color and has a UV resistance. The white type at Hardware Box Stores don't seem to hold up if left out in the sun and weather.

Thanks for the help. I found what I was looking for at http://pacermarine.com/catalogparts/duct.pdf . It is the black (UV) weather-resistant polyethylene "spiral wrap."