We're not going to agree on this one.
We can all find out what the law is, and what the government guidance is. But neither of these are perfectly clear (partly because they've been written in a hurry by fallible human beings, and partly because a bit of vagueness can be useful - do we want a menu written by civil servants of precise items of food that may be accompanied by alcohol to the exclusion of all other foodstuffs, or to be told that there should be a 'substantial meal'?) so we all need to do a little bit of interpretation of what the rules mean.
And we all approach interpreting the rules from different places. I think there are very few people who are deliberately going out and behaving in a way that they think is dangerous - but there are different views of what is safe.
So what does this mean for threads like this? Firstly, that we're not going to conclude it in a way that makes everyone happy, but secondly that we'll have to recognise that people may not take the advice given in good faith. So please let's not get too stroppy with people offering advice that we don't agree with.
For the actual question of 'should I go for a last play on the 483', my response would be
- what does the law say? If that means you can't travel then don't.
- what does the guidance say? Do you agree with the guidance?
- what does your view of how things are going with the pandemic say?
Only if you find that none of those questions has to be answered with 'don't travel' should you be on the ferry.