You have to hurry or the tide will turn and cover up the wonderful world of shapes and patterns and small creatures down at your feet. The best time to come to Gruinard Bay is when the tide is out and you can walk along the sand dipping in and out of puddles and peering into crevices and under rocks. The sand has a pinkish quality to it. Gruinard Bay is situated in a region of pinkish/purplish sandstone - Torridonian sandstone. The beach stretches for what seems like miles (only probably isn't!)
I'm sure I've said this before and I expect I'll say it again, but I'm always staggered by the perfect patterns that nature provides in such a seemingly casual way. If you're passing, especially when the tide is out, you must stop your journey and come down onto the beach - you couldn't possibly be disappointed.