Can you scuba dive to 6000 ft?

220 feet is about 67 metres. The pressure of air at this depth is about 8 bar (or atm). Using standard air the partial pressure (20%) of oxygen is 1.6 bar. This is the boundary where oxygen begins to become toxic and can cause serious health problems (and lead to death).

I am a diver with BSAC and the recommended maximum depth is 50m on air which is about 164 feet.

The alternative is to use other mixes of gas which usually require more advance training but they contain less oxygen so it is safer to diver deeper.

Summary, it is NOT safe to dive to 200ft on standard air