You could have flashing arrows, Tom Hanks dressed as Woody, standing by with a "keep your distance cowboy" sign, a holograph of a Ringwraith to block your path and a warning hooter that goes off in your right ear if you step too near another person and people will STILL not social distance. Those arrows are fine for normal non-idiots who haven't been living off grid for the past 12 weeks. Or have just woken from a deep cryogenic sleep. Then I'd forgive them for not knowing what life is like now.
People are idiots. The idiots are always going to be idiots, nothing you can do to stop them from being what they are. Which is of course an idiot. Or a Covidiot.
People who don't keep 2 metes away when they can (yeah I'm talking about you garden centre worker who squeezed right by me after I had been doing the right thing ALL the way round my anxiety ridden shop), should be put on a ship and cast out into the sea. You like being near people so much? Well you got your wish you muppets.
There's one box of latex gloves, 2 bog rolls and a stale packet of crisps. Enjoy your cruise.