INFORMATION FOR BODC SERIES REF. NO.    33921                  
                         Sea Floor Pressure Gauge Inventory Number :   6959     
 Start Time : 20 May 1977 1128 GMT                  Latitude  :  53deg 30.8min N
 End Time   : 08 Aug 1977 1213 GMT                  Longitude : 003deg 11.9min W
 Nominal Cycle Interval   :  900.0 secs         Sensor Depth    :     20.00m    
                                                Sea Floor Depth :     20.00m    
 Positional Uncertainty   : 0.1 to 0.5 n.miles                                  
 Depth Datum              : Instantaneous                                       
 Data Category            : Offshore sea floor pressure series                  
 Instrument Type          : Tide gauge (unspecified)                            
 Instrument Mounting      : Sea floor - fixed                                   
 Originator Laboratory    : Proudman Oceanographic Laboratory, Bidston, UK      
 Originator's Identifier  : 776/977/140                                         
 Additional information stored with the data:                                   
    Station QC, Liverpool Bay.                                                  
    Clock gained 15 seconds over 81 days, 21 hours; the cycle interval and time 
    values have been corrected.                                                 
    Instrument characteristics and calibration factors                          
           Aanderaa Pressure Recorder Type TG-2A, serial number 64              
           Original sampling interval          15 minutes                       
           Integration period                        100s                       
           No temperature correction made                                       
           Pressure sensitivity at 15.9degC   0.2584Hz/mb                       
           To convert pressure to elevation the following                       
           values should be used:                                               
           Density                            1025.3kg/m3                       
           Gravitational acceleration constant  9.814m/s2                       
    This tide gauge was deployed for Mersey Docks and Harbour Company  as  part 
    of  an  investigation  into  offshore and onshore tidal levels in Liverpool 
    Bay. No CTD casts were taken, but 10 sea surface  temperature  and  density 
    casts were taken between 23 May and 29 July.                                
 The following additional documents apply to this series:                       
  27731; I.O.S. Calibration and Data Processing of Off-Shore Tide Gauge Data    
  27806; Aanderaa Pressure Recorder Type TG-2A and WLR-5