I guess on the beach it's people coughing/ sneezing in close proximity to others. Handrails constantly used on the way down to the beach and along the front; keypads and other bits of the machine you use to pay for parking; drinks bottles, ice creams etc bought from a counter (with cash?) - all that rubbish on the beach is coming form somewhere (
); petrol stations to fuel up for the road trips; public toilets at the beaches; the chippy. Just guessing at examples and don't know the risk levels. All normal stuff, all could be mitigated to varying degrees, depending how seriously people take the threat.
We've now been to the beach a couple of times since full lockdown, shortly after dawn, no crowds, get in the sea without touching anything, get out, come home.