You appear to be intent on blaming the French for the refugee crisis. Like the NI protocol is the fault of the EU, and the problems caused by Brexit are caused by the intransigence of the EU. And the holdups in Dover are caused by the French.Where did I say the UK would prosecute infringement of EU/French law?
Your question was, what French laws have been broken.
Why are you ignoring the fact that someone entered France illegally and did not seek asylum to protect them from prosecution of the relevant immigration laws that they broke?
If they all chipped in to buy the boat and have joint title, then they are all responsible for the registration. The fact that its a DIY boat built from grow bag plastic is irrelevant. Its a vessel that needed to be registered. I suspect however the more serious crime is the immigration offence.
The moment one of these dodgy craft is sighted in French waters, there are grounds to investigate. Instead they escort them to UK waters and hand them over to SARs teams who escort them to the UK for processing.
Obviously you intend to continue with your blame-game diplomacy. It hasn't worked for the last thirty years, why do you think it will magically start working now?
Until we approach the problem with a collective responsibility mindset, there will be no workable solution. The blame game does not work, and the British public are beginning to see through it.