I could've flown between the two cities in a small plane, with the flight taking just over an hour. Instead, I decided to take a surface route - aboard a Baltic ferry.
The Polish company Polferries operates a number of routes between ports in Poland and Sweden. From Copenhagen, a bus takes its passengers to the Swedish port of Ystad, from where an overnight ferry heads to Świnoujście, right at the northwest corner of Poland.
I decided to give this a go. I'd never taken a ferry across the Baltic Sea before, and it would have the added benefit of saving me a night's accommodation in the expensive Danish capital.
This is how it worked. I walked from my hotel near Copenhagen's main railway station, to a dedicated stop next to the Hotel Plaza on the other side of the rail terminus. I could hear some Polish voices in the crowd milling around outside the hotel, so I suspected I was in the right location.
In due course, bus 866 showed up and we were on our way over the Øresund Bridge between Denmark and Sweden. This elegant structure has an ominous air in my mind at least, courtesy of the crime thriller series The Bridge:
I was surprised to have my passport checked, along with the rest of the passengers, on the Swedish side of the strait. It seems the recent refugee crisis has forced some temporary tightening of the free-movement Schengen Zone.
Past passport control, we passed through beautiful rolling countryside on our way to Ystad, the setting of another Scandi-noir crime series, Wallander:
There was less romance at the port at Ystad. Most of the bus passengers were taking a different ferry to Bornholm, a Danish island in the Baltic, and the bus pulled up outside that ferry terminal. The terminal for ferries to Poland was a long walk around the port in the open air. Lucky it wasn't raining.
Facilities were fairly basic in the Polish terminal, shared by two Polish ferry companies, and there was a long wait to get aboard. It was about 6pm when I arrived, and foot passengers couldn't check in until 7pm.
We then had to wait till 9pm to go aboard, amused only by a small snack bar in the terminal's waiting area. I had some sandwiches I'd bought in Denmark for dinner, but no drink.
Not having any Swedish currency, I managed to talk the snack bar owner into selling me a soft drink for 10 Polish złoty. He wanted more than that in krona, but grudgingly agreed (the drink would be a fraction of that price in Poland, but that's beside the point).
Finally the handful of foot passengers was led aboard by a Polish guy in a safety vest. We realised on approach that he had to insert us through the massive loading bay between huge trucks, so we could reach a lift to the upper decks. This was a bit thrilling, with just a hint of danger.
For all the industrial grit of the lower decks, the upper decks were quite pleasant - although with a touch of 1980s decor in the onboard restaurant and bar:
I headed to the uppermost deck to find my cabin. Having paid for sole use of a two-berth cabin, I was expecting something compact with bunk beds. So I was surprised to find it was three times the size of my Copenhagen hotel room, with two beds and an en suite bathroom:
When I stepped out onto the rear deck directly behind the cabin, I had this view of the fading light as we pulled out of Ystad into the Baltic:
Fortunately this was not one of those occasions on which a storm blows up in the Baltic Sea. It was a very smooth crossing, with a touch of gentle rocking, and I had a decent sleep.
When I awoke about 5.30am it was light outside, with the Polish shore already visible alongside as we navigated into the port within the mouth of the Świna River. I joined the truckers for a buffet breakfast (basic but filling), then mustered with my fellow foot passengers to be led through the deck of massed vehicles to the outside world.
I was pleased to see we had berthed right next to Świnoujście's main train station. I had a ticket for the express train from there to Warsaw at 6.37am, and it looked like I wouldn't have any trouble catching it.
Except... for foot passengers to leave the ferry terminal, we had to traverse an enormously long enclosed walkway that stretched west for what seemed a couple of kilometres. When I finally exited the main building, I had a long walk back down the railway line to the station, passing my ferry on the way (you can see the open 'nose' of the ferry's loading bay here):
I still had time to spare, however. I reached the station and found my reserved seat in the refurbished first class carriage of the 6.37 to Warsaw. I would have it more or less to myself until we reached the next big city, Szczecin.
As I was travelling first class, an attendant soon popped up to present me with a complimentary coffee, a tiny biscuit and the world's smallest tortilla. Seven hours to Warsaw? I was set.