On 3/21/2014 @ approximately 2151 hours, I was in my driveway and saw a near transparent blimp shaped object flying at a high rate of speed, moving from east to west, and appeared to be following a straight line flight path.The object was emitting a very low, almost inaudible pulsing humming sound.I noticed the object because I noticed it's movement as it flew over a nearby water tower. It was very large, it appeared to be larger than a C-130,but not quite as large as a C-17. I lost sight of the object as it passed behind some trees, I ran out into the field adjacent to my driveway to see if I could get a better look at it but was not able to find it again.As I stated the object was blimp shaped, but had what appeared to be a cylindrical object or attachment the ran across the lower front of the fuselage, perpendicular to the body of the craft.I would like to point out that I was an Air Defense soldier in the U.S. Army that received regular VACR (visual aircraft recognition) training, a retired volunteer firefighter with 21 years experience, as well as a detention officer for my local Sherriff's Office. I have grown up around military bases and see conventional aircraft on a daily basis.This object is not any aircraft that I recognize, and I feel it was moving too fast to have been a blimp.I also find it odd that the object was nearly transparent and appeared to be utilizing some sort of stealth technology. I believe the only reason I was able to see it at all is because the lights from the water tower illuminated it's edges.