"While the risk of a major explosion is believed to be remote, it is considered prudent to monitor the condition of the wreck."
https://www.gov.uk/government/publications/the-ss-richard-mo...
At least they know about it and check the site now and again...
...of improvements.
Seriously though, they more than know and check, it's carefully marked with large conspicuous buoys as well as constantly monitored in case someone fiddles with it and there are some pretty big, fast police RIBs round there. (had a nice friendly chat with them when they wondered if I was a drug smuggler.) Apparently they're cutting off the rusting masts (above water) sometime soon to reduce risk further. But there is not much that sensibly can be done to actually remove it, and there may not be much of it left that can actually go up.
Buried bombs that nobody knows are there are far more worrying... and the Germans have that problem rather worse than Britain does.
I mean if you were a drug smuggler you wouldn't have told them, would you?
"Oi mate, what you got that there? And no lies!"
"Evenin officer, just 200 kilos of cocaine, nothing fancy."
"Aight crackin, carry on. Wait, you got a loicense fer that cocaine?!"
At risk of personally identifying information... I guess I did volunteer this one.
I knew not many people pick a day in mid December to go sailing. I didn't know I'd be the only one out, the day they were doing a massive drugs bust. They clearly thought no real pleasure sailor would be there. Fortunately I am obviously a harmless WAFI* and the appearance of my kid's cheery grin in the companionway was enough to convince them. (Bringing them up hardy, you see)
They probably also realised that with their hundreds of horsepower it's not like my beloved 4KSB* is a credible getaway vehicle.
*Wind Assisted Fucking Idiot
**Four Knot S... Box