193.113.179.203 is indeed the IP address of
www.caa.co.uk - but it doesn't respond to pings.
If you try to connect to the IP address, you'll get the answer
No web site is configured at this address.
If you look it up, you'll find that 193.113.179.203 belongs to BT Corporate.
If you try to connect to
http://www.caa.co.uk it
should work. Does for me.