def apply_pressure_offset(df, p_col, p_off):
    """
    Applies pressure offset to pressure data
            
    Parameters
    ----------
    
    df :Pandas DataFrame
            DataFrame containing pressure values
            
    p_col :string
            Name of pressure column in DataFrame
           
    p_off :float
            Array containing ending ondeck pressure values
            
    Returns
    -------
    
    df :Pandas DataFrame
                DataFrame containing updated pressure values and a new flag column
       
    """
    df[p_col] = df[p_col] + p_off
    # Default to good data
    df['CTDPRS_FLAG_W'] = 2
    #new_press = press + p_off

    return df