To what approximate depth of water can submersible rigs drill?

• A. 400 ft (120 m) +- 50
• B. 175 ft (just over 50 m) +- 25
• C. 100 ft (30 m)
• D. 1000 ft (300 m)

Answer: (B)

Submersible rigs are built for shallow-water drilling, with the drilling unit positioned near the seabed while the rest of the rig operates from the surface. Their practical depth limit is about 50 meters because deeper water makes mooring, riser management, and stability far more difficult. So, the approximate depth they can drill is around 50 meters (roughly 175 feet) with a tolerance of about ±25 feet. In much deeper water, floating rigs such as semi-submersibles or drillships are used instead.