Cruise

I am fairly sure Wales and Scotland use the Pound, Ireland uses the Euro. Most ships offer currency exchange at the front office. That way you could get just enough for trinkets and a meals from the ship. For anything larger use a credit card. Getting some British Pounds before you depart my ease your stress level since you will be landing in England . Using an ATM debit card is another way to get local cash at all stops.

England, Scotland, Wales, and Northern Ireland use the Great British pound, the Republic of Ireland uses the euro, Iceland uses the Icelandic krona, and Greenland uses the Danish krone.

Bring as many Visa and MasterCard variations as you have, since AmEx is not widely accepted. You may not always be able to pay by card, in which case you would withdraw local currency from a local ATM with a debit card and try to spend it before departing that country. Coins cannot be exchanged in other countries, though bills can be.

Since some of this is new to you, please read through all the topics at https://www.ricksteves.com/travel-tips/money.

I'd leave the Amex at home. It's the least-accepted credit card internationally.

Use ATM's when you get off the ship. The pursor will sell you local cash but it's not a bargain.

I found ATM's around cruise ports weren't as numerous as airports. I'd suggest using Google maps to search for ATM's near where the ships anchor, so you don't spend too much time looking for them.

I used local busses or taxis to get into the town center, it helps if you can get some local currency right away to get started. Visa or Mastercard are widely accepted, but not necessarily for taxis, busses or small purchases. I bring my Amex for rental cars only (some of their cards have a great rental insurance option). Big places will take Amex but little ones probably won't.

I'm not sure if it's still true but you may want enough English pounds to use in Scotland. Once upon a time, English pounds were welcome in Scotland but not so much the other way around and banks here might not accept them for exchange.

Use BANK ATM cards when you need spending cash. There are many non-bank ATM's, and they'll not give you as good a rate on teh currency conversion. My Wells Fargo ATM charges $5 plus 5% discount on cash withdrawals--excessive. I carry a credit union ATM card that I just load up when we go on vacations, and it gives better terms.
We really use very little cash when traveling in this day of electronic banking. We use a credit card paying back 3% on all purchases whenever we can--like in hotels, restaurants, car rentals, etc. Credit cards have legal benefits vs. ATM cards, and many come with extended warranties on items purchased on the card and free rental card insurance.
American Express is now a travel agency, and their heydays are over. We don't use'em any longer.

The Republic of Ireland uses the euro but Northern Ireland, part of the British Isles, uses the pound sterling, as do Wales and Scotland. Your ship may have a currency exchange desk or machine. On no account use it, unless desperate. Very bad exchange rate and one more opportunity to be nickled and dimed by the cruise line.

While Iceland and Greenland both use Krona, it is different currency. Greenland uses the Danish Krona, Iceland has its own currency or ISK.

If you are spending time in Montreal (I hope you are, it's a wonderful city), make sure you get Canadian $. At present it's a bargain if you buy it with US$!

Bill, could you tell me which cruise line you will be on, that starts in Dover and ends in Montreal? I would love to be on that one and just take a taxi (never Uber for me) from the port to home.

Norma: try Seabourn

We cruise a lot and have done two transatlantic and love them.

Not sure what cruise line you are on.

Check out the Cruise Critic website for information on your ports, reviews of cruises and a roll call for your cruise.

Here are a couple of reviews of my cruises that may assist you. Recommend the Golden Circle Tour in Iceland, you can pay in US dollars.
British Isles
http://www.cruisecritic.com/memberreviews/memberreview.cfm?EntryID=221137
Transatlantic
http://www.cruisecritic.com/memberreviews/memberreview.cfm?EntryID=221136
North Sea/Atl and Transatlantic
 
http://www.cruisecritic.com/memberreviews/memberreview.cfm?EntryID=264272

You can buy and sell back currency with the Purser onboard. No, it isn't a bargain but the convenience for us vastly outweighed some savings....and I am as close with a nickel as anyone you're likely ever to meet. We needed varying currencies and for one day only; we got maybe $50 worth for the two of us so we wouldn't have to rely solely on our credit cards. I'm sure we got a poor rate when we purchased and probably a poorer rate when we sold it back, but these were small tranascations and those few dollars have faded into memory. It sure beat wandering a pier in St Petersburg, Stockholm and Copenhagen looking for an ATM when time is so limited to begin. Have a great trip, and safe travels.

Wish there was a LIKE button for Denny's reply. Sometimes time is more valuable than money. And then there's always the chance the ATM is down.

Regarding buying small amounts of currency on the ship. The exchange rate is terrible.

You don't really need local currency in Iceland, US dollars will do the trick, as well as credit cards. We paid for our local Iceland tour in US.

The other currencies involve the GBP and Euros. After you fly into England, suggest purchase some Pounds. We have been to Dublin twice and ATMs are available in the city. Most pubs and restaurants take credit cards, although AmEx is not accepted as much as Visa or MasterCard.