According to N.O.A.A., how deep is the water in the Gulf of Mexico and where is the deepest location?

I have waterproof charts for scuba diving the Gulf of Mexico that show the depth 75 nautical miles west of Clearwater, Florida is only 220 feet . My friend had one that covered the entire Gulf of Mexico that showed the deepest point was just over 300 feet. www.waterproofcharts.com I'm confused about this oil rig that's spilling oil into the gulf that's in 5000 feet of water and they cant get down that deep to fix the leaks. Didn't know the Gulf of mexico was that deep, especially within 100 miles of the coastline where all the oil rigs are located.