197.432—Surface-supplied air diving.
         The diving supervisor shall insure that—
    
    
        
        (a) 
         Surface-supplied air diving is conducted at depths less than 190 fsw, except that dives with bottom times of 30 minutes or less may be conducted to depths of 220 fsw;
    
    
    
    
        
        (d) 
         When a diver is in a physically confining space, another diver is stationed at the underwater point of entry and is line-tending the diver;
    
    
    
    
    
    
        
        (4) 
         A bell is used for dives with an in-water decompression time greater than 120 minutes, except when the diver is using a heavy-weight diving outfit or is diving in a physically confining space;
    
    
    
    
        
        (7) 
         Each diver has a diver-carried reserve breathing gas supply except when using a heavy-weight diving outfit or when diving in a physically confining space; and