I know that 'short courses' has been an hallowed and much-discussed GCA thread over the years. Here in the UK there are famously plenty of examples of the short par/short yards type as identified by Sean Arble, and not just amongst the Swinley Forest/New Zealand heathland cohort. By the sea, or nearly by the sea, Rye with its five short holes is, or certainly was, 6278 yards, with a par of 68 and a Scratch Score of 71 off the white (medal) tees, Harlech is 6403 (also with five short holes) off the whites, with an SSS of 72, and Aldeburgh (four short holes and no par fives) is 6378 with an SSS of 72 likewise. Off the very back Aldeburgh gets to 6603, SSS 73, for championships, and Harlech to 6629, SSS 73, whilst Rye I think reached the elephantine heights of 6454 when it hosted the English Championship a few summers ago. I somehow doubt that anybody, even the most accomplished GCA practitioner, has ever walked off any of these three thinking 'what a pushover', even in still conditions, let alone in a wind...the shortest course for a major British male event in the post-war period was probably The Sacred Nine, when it hosted (doubtless through the guidance of Gerald Micklem) the (then) English Golf Union Champion of Champions event fifty years ago this year, and would have played to 6218 yards, give or take: incidentally 142 strokes was the best 36-hole score recorded at Worlington by the cream of English amateur golf on that occasion. Luffness New is the only rival that I can think of: a medal-tee 6104 yards for Open Championship Qualifying (for Muirfield Opens) seems admirably self-restrained, although I don't know to what extent, if any, the course was lengthened for these purposes in the 1970s and 1980s.