I've done a lot of walking year round on beaches. The hardness can vary a lot, depending on recent weather. Some days my trainers hardly leave a sole print, but sometimes I sink 30 mm into the sand, at each step, in the same place. Have a beach checked shortly before you use it. I've walked on good hard sand near HW Spring tide mark, when there were Neap tides, and you could have parked all day
And phone the police (and Coastguard?) in advance. Also tell Air Traffic. With mobile phones, everyone seeing you from a distance is likely to dial 999.
I have never landed on a beach that was not an airfield.