What do the red R and O's stand for on the fixture list???
please help

The letters R, O and S relate to different types of Silver Tiller events.  R indicates the venue is on "restricted" water, i.e. small lake or a river, etc.  O is for "open" water - larger inland water venues - and S refers to "sea" venues.

The other letters refer to local circuits - M for Midland Circuit, W for South West Circuit, and T for the River Thames Series.

It does inform you at the top of the page!