In 1999 Worthing Rebels was formed, before changing the name in 2000 to Worthing Thunder.
Below are the season achievements.

Season Div. Pos. Play Offs Nat. Trophy BBL Trophy Cup
1999–2000 NBL 1 2nd Quarter-final Runner-up n/a -
2000–2001 NBL Conf. 2nd Runner-up Semi-final n/a 1st Round
2001–2002 NBL Conf. 6th Quarter-final Runner-up n/a 1st Round
2002–2003 NBL Conf. 4th Quarter-final Runner-up n/a -
2003–2004 EBL 1 5th Semi-final Winners n/a Quarter-final
2004–2005 EBL 1 5th Quarter-final Runner-up n/a Semi-final
2005–2006 EBL 1 1st Runner-up 2nd Round 1st Round Quarter-final
2006–2007 EBL 1 1st Winners Runner-up 1st Round Runner-up
2007–2008 EBL 1 3rd Quarter-final Runner-up 1st Round Runner-up
2008–2009 BBL 11th DNQ n/a 1st Round 1st Round
2009–2010 BBL 8th Quarter-final n/a Quarter-final 1st Round
2010–2011 BBL 11th DNQ n/a 1st Round 1st Round
2011–2012 EBL 1 4th Quarter-final Quarter-final n/a 3rd Round
2012–2013 EBL 1 7th Runner-up 1st Round Quarter-final Semi-final
2013-2014 NBL 1 10th  DNQ  Semi-final    2nd Round
2014-2015 NBL 1 7th  Quarter-final Quarter-final    Semi-final 
2015-2016 NBL 1 10th  DNQ Quarter-final    Runner-up
2016-2017 NBL 1 12th  DNQ Semi-final    4th Round 
2017~2018 NBL 1