I agree with NCWayne about using a large excavator to clear the mud away from the dozer once the pond is drained, but make certain that the excavator stays on FIRM GROUND or you will have TWO stuck machines. If it's a Large pond, you may have to set up a Drag-Line to remove the mud instead of an excavator.
The only experience I've had with a buried dozer was back in 1978 when I worked for a Gold & Silver Mining operation in Nevada. We had heap-leach pads 100 feet wide by 400 feet long by 15 feet high that had been soaking in Sodium Cyanide solution for over 1 month, when our supposedly competent dozer operator decided that he was going to take our large Komatsu dozer (D9 size) and "turn over the pad". He walked the Komatsu up the side of the pad on boulders, but as soon as he got off the boulders he buried the dozer to the point where only the top 1 1/2 feet of the exhaust stack were showing. We now had a large dozer completely buried in VERY CAUSTIC & EXTREMELY DEADLY mud, (Sodium Cyanide has to be mixed with Sodium Hydroxide (caustic soda) to keep it highly Alkaline. - Cyanide with ANY type of acid creates CYANIDE GAS, - INSTANT DEATH).
To remove the Komatsu we used two 980 wheel-loaders to dig it out. Next we used all of our heaviest chains & cables hooked to two huge 50 Cubic Yard capacity Haulpak haulage trucks. The chains & cables promptly SNAPPED. We ended up having to get Anchor Chain for a large ship, in order to pull out our Komatsu. Once we got it out, we spent the next two days washing off the mud with fire hoses. Meanwhile, company management had put it up FOR SALE - CHEAP!
A friend of mine bought the Komatsu when I told him about it being for sale after what had happened to it. He hauled it home & proceeded to thoroughly flush out the engine, trans, finals, EVERYTHING. I saw the Komatsu several years later & it was running & operating just like a new machine and to the best of my knowledge it is still going strong.