What would the pressure in pounds per square inch be in 160 feet of water

Fresh water has a density of 62.4 \frac {lb} {ft^3}, so at 1 foot depth the pressure is 62.4 pounds per square foot, or in terms of PSI per foot of depth:

62.4 \frac {lb} {ft^3} = \frac{ {62.4} \frac {lb} {ft^3} }{144 \frac {in^2} {ft^2}}= 0.433\frac {lb} {in^2 -ft}.

So at 160 feet, you have 0.4333 \frac {lb} {in^2 - ft} \times 160 ft = 69.3 \frac {lb} {in^2}


The number would be a bit higher if you are interested in salt water, as salet water is about 2.7% denser than fresh water.