http://www.genealogyworld.net/rose/maritime/b_aliwal.htmlTry pasting the above into your browser - this link should take you directly to the Aliwal passenger list and some background re the shoal etc.
On this passenger list, which is taken from a newspaper shipping column (inaccurate spellings of passengers' names were a feature of these columns), the ROBARTS family is given as ROBERTS, but there's no question that it's the correct family. I have no individual details on the family immediately to hand; it would require some dedicated digging. There is a deceased estate file in Pietermaritzburg Archives for William Robarts who married Elizabeth Ward born Povall: see
www.national.archives.gov.za/ reference below -
DEPOT NAB SOURCE MSCE TYPE LEER VOLUME_NO 0 SYSTEM 01 REFERENCE 19/4 PART 1 DESCRIPTION ROBARTS, WILLIAM EMERY. (S/S ELIZABETH WARD, BORN POVALL).
STARTING 19030000 ENDING 19210000 REMARKS SEE MSCE163/49 IO408/1903 R6/3804B.
The best source for general info on the Byrne settlers, sorry not online, is John Clark's book 'Natal Settler Agent: The Career of John Moreland Agent for the Byrne emigration scheme 1849-51' published by AA Balkema Cape Town 1972 ISBN 0 86961 019 8
Almost impossible to discuss the complex topic of settlers' land allotments on RootsChat!
You - or your friend - need to do some reading on the Byrne settler topic to get the big picture.
Shelagh Spencer's volumes, so far up to surnames beginning with 'G', of British Settlers in Natal - she does have a couple of mentions of William Robarts, Emery's son, scattered amongst the text published in the first 7 volumes, and eventually there will be a special section for ROBARTS when the 'R' surnames are reached - but a long way to go before that happens, the volumes appear very slowly, Spencer being incredibly detailed in her research.
The dive sites you mention are inaccurate in their info concerning the naming of the Aliwal Shoal - it is a fairly common misconception; the origin of the name is definitely as stated in my previous mail.
best wishes, Mole