Gliders in the UK use a collection of frequencies on a national basis for different purposes.
They do not need to hold an R/T licence (although I think this should be a mandatory). Therefore dispensation has been given to use the following frequencies without holding a licence. Due to this, r/t procedures are appalling and I cringe every time I here somebody on the radio.
129.9 MHz Ground to Ground only. Used to run airfield.
129.975 MHz Control Purposes at approved sites only (within 10NM and up to 3000 feet). This is a useful frequency when approaching a large airfield eg Lasham, Bicester.
130.1 MHz Gliding Competitions (primary). This is also used ground to air.
130.125 MHz Gliding Competitions (secondary), and Lead and Follow training.
130.4 MHz Cloud Flying. Gliders will enter cumulas in free airspace and will only call on this frequency. If flying IFR then think twice before flying through clouds!
To contact clubs best to use 129.975 and 130.1
Hope this helps.