Subsea Pressure Regulators

Subsea Pressure Regulators are designed to operate at depths up to 10,000ft (3,000m), and can be completely sealed to operate at topside ambient pressure conditions, or they can use the external seawater pressure as a reference pressure, thereby making them utterly unaffected by external pressure conditions.
 
The 'bucket handle' version of this regulator allows for subsea adjustment by ROVs.  There is also an electric-actuated option that enables remote control of the regulator for applications where manual adjustments are difficult or time-consuming.