according to the blurb....channel sevens premium streaming app has all sports on demand...cost $20 (free with telstra) I don't have it so its up to someone else to confirm.
They only show the sports that are the most exciting to watch and will have the most viewers, $$$$$$$
thats why they show golf, dressage and synchronised swimming over the windsurfing and sailing,,,, apparently.
Its what more Aussies want to see. 
according to this www.yachtingworld.com/rio-olympics-2016/how-to-follow-rio-2016-sailing-olympics-71107 you should be able to watch it online on BBC, that is if you are in the UK, which I assume you're not.
Look up a VPN or proxy service, such as Private Internet Access or Unotelly. I think most of them offer free trial for few days.
If you want to watch it on TV, instead of computer monitor, get a Chromecast (about $40) and cast from PC to TV. Obviously this will take little time to set up and depend on your internet connection.
There may be other online streaming channels, just google it, the approach above should still work.
Yep channel 7 app give s access to all sports you can select and playback all videos in full. Free if you have a Telstra account just create a log on id. Beats trying to watch on the TV.
cricfree.tv/watch/live/olympics-sailing-live-streaming-cricfree
it has a few pop up ads just click the the little dark gray "x" to clear not greatest quality but ok
