Thirty minutes after we leave the EU tonight, a ferry will begin its normal nightly journey from Cairnryan bound for Belfast.
On board will be a sample of the 850,000 lorry loads of goods which travel from GB to Northern Ireland every year.
Northern Ireland purchases around £10bn worth of goods from GB every year.
The journey these goods take across the Irish Sea and any checks required will now become the focus of the Brexit negotiations.
For over three years, the discussions focused on avoiding a hard land border between Northern Ireland and the Republic.
Prime Minister Boris Johnson’s deal with the EU resolved that, and removed the so-called backstop.
But after 11pm tonight, the focus will turn to how to manage GB goods travelling to NI, which are then at risk of moving into the EU through the Republic of Ireland.
The EU maintains checks on goods coming to Northern Ireland will be required.
Boris Johnson has said there will be no new checks between NI and GB.
While nothing changes in Northern Ireland after 11pm tonight, businesses are preparing for the changes which could come at the end of the year.
The EU/UK trade negotiations over the next 11 months need to decide how extensive any checks should be and where exactly they should take place -before goods leave ports in GB, for example at Cairnryan, or when they arrive in Belfast, Larne, Warrenpoint or Foyle.
Either way, it will mean more paperwork for firms bringing goods into Northern Ireland, possible delays as any checks are managed, and increased costs in managing the changes.
The Brexit clock has been reset to countdown to 31 December 2020.
But as one business leader has pointed out, trade deals on average take four years to negotiate.
It will be quite a feat if Boris Johnson can tie this all up in the next 11 months.