In reply to Mike Hutton:
We did in May. It was still a thing then. You can't drive any further than the cemetery so there's an extra maybe 200m to carry stuff. Understandable because erosion was a (quite striking, obvious, and slowly recovering) problem.
No water supply that we could see. Nearest tap, and toilets, a mile or so back up the road. There's an honesty box on the gatepost and sign asking for donations but also slightly strangely reminding you in a roundabout way that it's your right to wildcamp anywhere. We were happy to put in but remember thinking the wording was a bit odd.
Edit: I presumed you meant down by the beach but now realise that might not be what you meant by "the field close to Sheigra cliff tops". If there's another field up top, sorry can't help.
Post edited at 19:20