How Is Tension Calculated in a Submerged Object's Lifting Cable?

[kiwikahuna]

Homework Statement

A seagoing crane lifts a sealed safe from a sunken ship. The average density of the safe is 5.3 grams/cc and its mass is 120 kg. What is the tension in the lifting cable when the safe is still submerged?

Homework Equations

Pressure = density *gravity* height*
Buoyant force = mg

The Attempt at a Solution

I calculated 5300kg/m^2 * 9.81 m/s^2 * 120 kg

The above is what I got so far but I'm not sure I'm doing it right. Any help would be greatly appreciated.

 

[CaptainZappo]

Draw a free-body diagram of the object. From the context of the problem, there must be no net force acting on the object. What forces act in which directions?

Note: the buoyant force is equal to the weight of the DISPLACED fluid, not necessarily equal to the weight of the submerged object.