In reply to Toerag:
> As he lives in London and the planes from Gatwick will be full unlike the boat* I suspect the fuel cost per mile is lower to fly.
> *My wife and kids went on the fast ferry to France at the weekend. They're only using about a quarter of the seating as they can't clean it fast enough during turnaround and its massively under capacity.
Sure - but that’s a hopefully temporary and contingent state of affairs. And also ignores the marginal costs of travel, which will be low if the boats are under capacity.
Still, the point remains: if we need to change our behaviour and build both new habits and new norms, wouldn’t it make sense to start that now?