China has no submarines in the sea.

https://www.globaltimes.cn/page/202108/1230982.shtml

Media report claiming UK carrier group spots PLA submarines ‘not credible’,  Chinese military experts said. The report is trying to boast of the UK’s anti-submarine capability, through the means of belittling China’s submarines, Song said. It is possible that the PLA used the HMS Queen Elizabeth aircraft carrier strike group as an imaginary target for practice, said a submarine expert .
It is also possible that the Chinese submarines intentionally revealed themselves after having accomplished their missions, sending a warning to the UK carrier group, experts said.
Now, the UK media is making up this groundless lie to make the UK seem like a victim, experts said.

Those submarines weren't there, they were hard to detect and were doing practice, and maybe were giving warning by being there, so it's a lie by the victim to insult submarines when they weren't. China is credible when UK targets are not credible or targets. No submarine is a submarine. Go away and don't read this.