QUALITY ASSESSMENT OF SEA LEVEL DATA                
                                           by the                               
                   UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER     
                                 JOINT ARCHIVE FOR SEA LEVEL                    
                                       updated: 07 Dec 1998
              Station  : Richard's Bay             Latitude:  28 48.0S
              Country  : South Africa             Longitude: 032 05.0E
              JASL #   : 188A                 Time Meridian: 030E (GMT + 2 hr)  
              GLOSS #  : none     TOGA #: none       NODC #: 32038201
              Contributor  : Directorate of Hydrography                         
                             Maritime Headquarters                              
                             Private Bag Retreat                                
                             7965 South Africa                                  
              Originator   : same                                               
              Original Data: analog (LEA,KENT); digital (SRD)                                             
              Instrmnt Type: 1) LEA float-type 1985 - 1987
                             2) KENT float-type 1977 - 1984, 1989 - 1997.
                             3) SRD acoustic tide gauge 1997
              Digitzd Intvl: hourly (LEA,KENT); unconfirmed (SRD)
              Present Data : Hourly, daily, and monthly values obtained by:     
                    Hourly : manually filtered raw data (LEA,KENT); 
                             unconfirmed (SRD)
                    Daily  : 119-point convolution filter (Bloomfield, 1976)    
                             centered on noon applied to the hourly data        
                             with respective periods of the 95, 50, and 5%      
                             amplitude points at 124.0, 60.2, and 40.2 hours    
                    Monthly: Simple average of all daily values; calculated if  
                             7 or fewer days are missing                        
              Span of data : 01 Jan 1991 - 31 Dec 1996
              Gaps > 1 mon : 15 Jun 1992 - 26 Nov 1992;07 Dec 1992 - 07 Jan 1993
                             11 Jan 1993 - 28 Jun 1993;27 Jul 1993 - 21 Sep 1993
                             15 Oct 1993 - 13 Jan 1994;29 Sep 1994 - 22 Feb 1995
                             09 May 1995 - 07 Aug 1995;27 Nov 1995 - 18 Jan 1996
              Time Refernce: GMT (hours 00-23)   Space-filler Flag   :-9999     
              Units        : millimeters         Missing Data Flag   : 9999     
              Existing     : Yes                 Operational         : Yes      
              Sat. Trans.  : No                  Distribution        : 1991-1996
              Refernce Levl: All heights have been referred to the station 
                             Chart Datum which is linked to fixed benchmarks.
                             The Chart Datum is -0.900 meters relative to the 
                             Land Levelling Datum in all ports of the Republic
                             of South Africa and it approximates the Lowest
                             Astronomical Tide.  Benchmarks:
                             * SCH3: 3.429 above MSL
                             * SAN 84.2: 3.422 m above MSL
                             * "New GPS": 3.459 above MSL
              Comment      : The numerous data gaps hinders the quality of the
                             data and of the quality of the harmonic constants
                             from which tidal predictions and hence residuals
                             are derived.  The residuals contain significant
                             fluctuations yet it is usually unclear if the
                             signal is due to bad data or due to poor tidal
                             predictions.  Only extreme fluctuations noted.
                             
                    CI MISSING              REPLACED GAPS     QUESTIONABLE      
              YEAR (%) DATA                 OR BAD DATA       FLUCTUATIONS      
              ---- --- -------------------- --------------- --------------------
              1991  83 15-18,32-38,44-50,   (08)076-(21)076 4-5,209-210
                       67-74,87-102,134-    (22)083-(11)084
                       140,154-164,189-197  (07)087-(16)087
              1992  34 3-8,16-23,30-43,53-  (07)015-(22)015 23
                       60,79-84,142-153,    (22)065-(13)066
                       167-331,334-338,
                       342-366
              1993  11 1-7,11-179,186-194,  (08)011-(21)011 7-11
                       200-203,208-264,277- (13)273-(21)273
                       284,288-365
              1994  40 1-13,31-38,46-49,87- (22)160-(09)161 73-74
                       97,105-115,124-136,  (10)175-(17)175
                       147-153,186-196,200-
                       209,215-229,241-365
              1995  35 1-53,59-73,90-94,96- (08)059-(20)059 103-117
                       103,115-122,129-219,
                       222-240,275-284,312-
                       314,331-365
              1996  77 1-18,22-36,52-72,    none            71-80,90,285-291
                       156-165,316-341,366