The Eurostar goes from Paris to London, it doesn't go to Dublin.
From the Airport you can the Underground train to Euston, and from Euston you can get a train to Holyhead which is where the ferry goes from.
Ireland is an island and London is a on neighbouring island. There is no connecting bridge, given the distance between them. So you cannot get a train from London to Ireland. The best you could by train, is to travel by train from London to Holyhead or Liverpool, and from either of them take a ferry to Ireland. You can also look at other ways, such as flying. Yes you can do it however, the only simple way from London is: the London to Fishguard train that stops in Bristol, Cardiff and Swansea. From Fishguard you will change to the Stena Ferry for Rosslare. Here you'll get a train to Dublin where you can change for all main stations in Ireland
The journey via Edinburgh is 2 hours 50 minutes from Aberdeen to Edinburgh then 7 hours 13 minutes from Edinburgh to London and covers 531 miles. Plan for extra time to change trains in Edinburgh cheers, Skunkfarmer ... New Hampshire USA
There are but I really would not go for it unless you are a seasoned traveler. Go for CDG and take the train into the valley. There is an airport at Tours which is serviced from London Stansted and Dublin, Ireland
Dublin is in Europe, so you could say the answer is zero. The nearest European country would be Wales, which is less than 2 hours by boat. To mainland Europe, which is probably what you mean, it can be done in less than 2 days. There are no actual ferries from Dublin to any mainland Europe country.
There are no flights that operate from any of the Nottingham area airports to any of the London area airports, however the flight time from London to Dublin takes around 50 minutes - 1 hour 15 minutes.
There is no train from Dublin to Waterville. You could get a train to Tralee or Killarney in county Kerry, the county that Waterville is in.
That depends on where you are travelling FROM!
It is cheaper to fly from London to Dublin than to rent a car in London and drive (and catch a ferry across the Irish sea) to Dublin. If you shop around you can get some very good value air fairs from London to Dublin.
London is better
280 air miles between Dublin and Heathrow, London.