Little Dog,
This is just my own experience, so gain what you can from it. Last Fall, I rented a D-8 to muck out/deepen my existing pond. $25 worth of 'insurance' paid for ANY breakdown, even a roll-over, I might have. Did the same again this year with a D-7, and the feeling I get looking at the job I did is consistantly awesome. For what cost me $8,500 would have been well over $20,000 if a contactor had performed the work. Advice? If the equipment renter will not provide insurance? Run away, run away! BTW, what size Cat are you considering? A D-8 drinks about 100+ Gals a day, but at a reduced "off road fuel" price, plus don't forget hauling fees. The advice I got from an old timer worked: "start pushing the dirt. It will go where it wants to go." And my pond worked out just fine. (I added lots of "shape and taper" to that advice. ) Warning: a large Cat weighs 30 to 40 tons, so if there is even a HINT of wetness, figure in renting another Cat of at least same size to pull it out.
