Most economical transportation from London to Amsterdam

Economical; depends on when you buy the train or plane ticket in advance, a boat ? nope; takes much too long and the weather...
The train takes from one city center to other; the plane outside the city centers, and then you have to commute in.

I think I would fly back to London after a cruise versus taking a train

Most economical: Flight from one of the cheapo airlines booked 6 months in advance. Some cheap seats are already sold. Easyjet ( https://www.easyjet.com ) is currently offering flights from Stansted, Southend, Luton and Gatwick on that date, starting from £21. You need to add travel costs to and from the airport to that, plus any luggage costs.

Most comfortable: Eurostar city centre to city centre. Website: https://www.eurostar.com has fares from €40 for 27th April

Most memorable: Ferry. Train to Harwich, ferry Harwich - Hook of Holland, train to Amsterdam. info here: https://www.seat61.com/Netherlands.htm#train+ferry

Really, kind of stuck with flying from Heathrow to Amsterdam. For other readers the most economical way would have been an open jaw ticket into Amsterdam and home from London and saved close to a day of travel. Without checking schedules I would guess that economy airline like easyJet would have been the most economical. But easyJet doesn't fly out of Heathrow. Since your are at Heathrow it doesn't make much sense to go into London to take a train or even to Stanton for easyJet. I would see what the best available flights would be from Heathrow to Amsterdam. Give yourself at least a four hour, maybe five hour, window to clear immigration and customs. Where does the trip end? Amsterdam ?? Our responses are kind of limited. Why didn't you ask us this question six months ago when we could have really provided some assistance?

Frank has nailed it: For future trips, try to book a multi-city flight into your first destination (Amsterdam in this case) and out of your final destination (London on this trip). That is often not much more expensive than a regular round-trip, and in this case it would probably have saved you money. In any case, with a cruise on the line, it would even be worth paying a bit extra to reduce the number of travel legs and, thus, the possibility that something will go wrong.

Your dates are wrong. Friday is the 26th April.

You don’t have time for the boat.

The value airlines don’t use the expensive Heathrow and the best value tickets should have been bought months ago when they were first available. Had you booked a ticket through to Amsterdam, if there is any delay to your inbound flight, then the airline would have to put you on the next available flight. As you haven’t, you will need to allow a margin for delay for your onward flight. BA and KLM fly from Heathrow direct. Most flights on this route cater for business traffic and therefore operate early morning and in the evening. You will need the afternoon KLM flight.

Alternatively, you can head to Gatwick (allow 4 hours for the transfer) plus a margin for your flight being delayed. However, the first flight you could make departs at the same time as the Heathrow flight, which makes the transfer rather pointless.

There are only 2 trains daily that run through to Amsterdam from London. You will arrive too late for the morning train. The later service at 17.31 arrives at 22.12. Therefore, you would have to take a train to Brussels and change there. The plane would be easier.

Your dates are wrong. Friday is the 26th April.

Jennifer is correct.

Where you looking at a calendar for a Euro based entity? I have found that they often use a Mon-Sun, not Sun-Sat format that is used in the US.

Currently, KLM have flights from Heathrow to Amsterdam for around £90 at 08:40 and 11:45am
In the absence of an open jaw flight directly from the US into Amsterdam.
I would think this would be easiest and you would probably not save that much money flying from other airports once you've factored in transfers etc (Gatwick Amsterdam is currently showing as £57 for the cheapest flight on 26/4)

I cannot imagine changing airports in London after a (for me) sleepless overnight flight. I would pay whatever it takes to fly from Heathrow--and I am an extremely frugal traveler.

Somehow I would not feel as stressed if I needed to take the tube (or a train) into town. It's the potential for traffic disasters during a bus transfer that really worries me, though I am aware that things occasionally go wrong on trains and tube as well.

That Saturday the 27th is King's Day.

Should spice things up in Amsterdam just a little. Leave LOTS of time to get to your boat. Transportation in Amsterdam on King's Day (used to be known as Queen's Day, recently changed) is always a bit interesting.

Worth reading up on.

Wear orange. All day. Head to toe, including the toes.

I want to thank ALL of you for spending your valuable time to help me out & give me some answers to my questions!! WOW, you all are soooooo AWESOME!!

I had heard about "open jaw" but didn't really understand what exactly it meant. I NOW KNOW WHAT IT MEANS!! (LOL)

I just booked my tickets 2 days ago, so was very last minute. I just did a "pretend" booking for the "open jaw" and it added 800.00 plus dollars to each ticket. So in this case, not just a few dollars more. HOWEVER, if I had had all the facts in front of me, I might have ended up booking that!!

Does the train to Amsterdam leave from Heathrow (or near by??). I was wondering if I would leave the airport (since we arrive at 6:25 AM) and do a few touristy things & then come back & leave on the train or plane??

OR, just get to The Netherlands ASAP as our cruise leaves on Saturday, April 27??

If you take the Eurostar (the train which travels to Europe via the Channel Tunnel), it is at St Pancras International station, about an hour on the Underground from Heathrow, and you need to check in an hour ahead of departure time. That is because after check in you have airline type security checks, then UK departure border checks (have your passport out and available) and then French border checks (because they are the first country that your train arrives in, even if you are going to Amsterdam, coming out of the tunnel you are in France) (have your passport out for them too) before you can get to the waiting room where you wait for your train to be called.

So, to directly answer your last question, no the train is not at Heathrow. Some people will tell you to take the Heathrow Express train from Heathrow to Paddington station, and then get a cab or tube train to Kings Cross/St Pancras but I believe that it is just as easy, just about as fast, and much cheaper just to get on the Tube at Heathrow and get off at Kings Cross/St Pancras and go upstairs for your train.

You have already heard of the difficulties and expense of taking a plane to Amsterdam on a separate booking. That applies for both train and plane, but at least if you are at Heathrow already you don't have far to go to get to your plane and when it goes it is considerably faster than the train.

It is a difficult situation you find yourself in. We'll do what we can to help you with information.

BA does price to compete with the low cost carriers on city pairs. If you search directly on their web site or app, I’m seeing one way Friday evening flights for LHR-AMS in the 68pounds hand baggage only or 81 pounds for checked bag range.

Store your bags at the Heathrow left luggage office for the day, get out of the airport to Windsor or something to get some daylight, which helps get over jet lag, and get back to the airport around 3 for your 6 or 7 pm flight

It’s likely going to be far less hassle than anything involving moving around to catch the next transit option

merryvm, thanks for posting your actual experience with a trial open-jaw booking. In fact, most people find that there is little or no penalty today. Perhaps the website or the way in which you made your trial booking affected the results. (You can get slightly better advice here by filling in your home city in your profile - we don't know if you are coming from a remote place or what ... ) Amsterdam has a huge airport with lots of service. And it's a better travel experience than Heathrow IMHO. What's the "change fee" for your current air booking? Note that BREXIT could DRASTICALLY affect the Eurostar trip. When it first started, they had a stop for customs/immigration in Brussels on the return trip, and that was without Brexit!

In the same way, note that booking bargain airlines carelessly can leave you exposed to seat reservation fees and luggage fees, even for carry-ons. Sometimes it's best to accept a "luxury" (!!!) package they sell that includes seat and luggage fees. The longer you wait to buy the Eurostar, the more it will cost. It's a very comfortable trip, but looooong.

I wouldn't wait around for 12 hours for a flight to Amsterdam, especially after an overnight flight. Take the Tube to St Pancras/Eurostar and enjoy the scenery on your way to Amsterdam. You can relax, snack, nap, etc. It's fairly easy and painless, IMO, considering your situation. You'll be in Amsterdam before your flight even takes off.

Hopefully when you were doing your dummy booking on the open jaw you clicked on Multi-city and didn't try to price it out by doing 2 one-ways.

Where you fly from can make a difference. I fly from an end of the line destination and when the seats are filling up on my small puddle jumper to the hub they really go up in price!

Merry, you confused me by your post title: "transportation from London to Amsterdam" and you didn't say you wanted to go to Amsterdam on the same day as you arrived, so I described Eurostar (which departs from central London), and all the other airports (which are reachable from central London).
What you actually want to do is get from Heathrow airport to Amsterdam (which is not the same as starting in London), and after arriving on a transatlantic flight (which means you cannot predict your time). From Heathrow you only have transport into central London, or flights from the airport.

Travelling from an airport location is a different question to travelling from a city centre.