You might want to try a local university, maybe a physiology department. I had mine done a while back at Syracuse University. I was pretty disappointed with the results at the time. You could see veins in my legs and arms, and definitely had a six pack.
They said I was 12% bodyfat and I was shocked. I figured I was under 5% I made them redo it and the results were the same. I really would like to see a 6-8% bodyfat level in real life. The skin must look like plastic wrap.
I had the same experience recently in South Florida at Florida Atlantic University, in Davie. I'm very lean, with veins in my abs, quads, etc. The hydrostatic weighing method said that I was 21% and then 20% bf. I'm definitely below 10 %, probably closer to 5% than 10%.
You can get bad readings if you have a hard time getting all of the air out of your lungs before they dunk you. I know of pros that tested above 20% and below 0% using underwater weighing. It's not as accurate as it's made out to be.