[Parothwk20]

I am unable to get the correct answer to the question

A scuba diver is experiencing a pressure of 5.0 atm.  To what depth in feet has he dived? 

I know that the pressure at the surface of the water is 1 atm
I know that the density of mercury is 13.6 g/ml
I know that the density of water is 1.0 g/ml
I know that there are 3.28 feet in one meter.

However, I have no idea which equations to use?  I continue to get the answer 54.4 feet but I dont think that is right?  I'll take any direction towards the correct answer, thanks

[Padfoot]

http://www.grc.nasa.gov/WWW/K-12/WindTunnel/Activities/fluid_pressure.html