KimPossible

Do you recommend we buy tickets for Le Havre to Paris online or will there be enough seats when we arrive? It will be a Tuesday around 8 am that we need to board the train from our cruise ship.

StCirq

How can anyone answer this question? Probably you'll be fine, but who knows? Maybe you're traveling at a peak time of day or on a holiday or some time when French school kids are on the train in droves.

And you can probably get a better fare online. So why not book now if you can accurately guage when you need to travel?

kerouac

Reservations are not obligatory on that line, so tickets never sell out. If the train is full, people might sit on their baggage at the ends of the cars. But there is no reason to think that the train will be full on a week day.

GeoffHamer

The trains from Le Havre to Paris go via Rouen. The train might be full from Rouen to Paris but it's extremely unlikely to be full from Le Havre which is the start of the train's journey. If you haven't booked seats in advance, look for unreserved seats (the reserved seats are marked with labels) and you'll be fine. If you do book seats in advance, a full-fare ticket is still valid on other trains (though without reserved seats) so you still have flexibility.

PalenQ

And if you pay a bit more for 1st class you'll probably be one of the few amongst the many empty seats in that class.