What is Absolute Pressure and How is it Related to Gauge Pressure in a Pool?

[NP04]

Homework Statement

You are originally 2.0m below the surface of a pool.

If you swim to 4.0m below the surface, what will happen to the absolute pressure on you?

a) Absolute Pressure Quadruples
b) Absolute Pressure More than doubles
c) Absolute Pressure exactly doubles
d) Absolute Pressure less than doubles

Relevant Equations

P gauge = ρgh
P total = P atm + P gauge

I think I can eliminate A because the equations depict a linear relationship. Since the gauge pressure is in a linear relationship with the absolute pressure, I would say exactly 2, but the answer is d.

 

[Orodruin]

Is the surface pressure zero?

 

[jackwhirl]

How would you define absolute pressure? (In your own words.)