=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 11-Jun-1991 Sultan Shoal 555/021 RLR(1986) is 10.2m below Brass Bolt =========================== FOLLOWING PSMSL DOCUMENTATION ADDED 12-Jul-1993 Sultan Shoal 555/021 RLR(1986) is 10.2m below Brass Bolt =========================== FOLLOWING PSMSL DOCUMENTATION ADDED 12-Oct-2010 Benchmark for the period 1969-1979 was Dampier Survey 'T' mark 6.500m above Datum 1969-1985. 1980-1985 benchmark was Brass Bolt 5.004m above Datum 1969-1985. 1986 onwards the ACD changed to 4.922m below the Brass Bolt. In 2009 a new jetty was re-constructed ACD remained the same while Primary benchmark is now Cut Mark 4.941m above ACD. Because of the building of the new jetty there is a gap in the data Jan 2008- Sept 2009.