Flying through one of the London airports during a peak weekend in August tests any passenger's nerves to destruction. Earlier this month, Stansted airport exemplified the appeal of flight-free travel. After the barely penetrable mass of humanity at check-in, security was overstretched and undignified, and the shuttle to the western satellite was packed tight.
In my experience, departure screens at airports mostly comprise a succession of fibs: "boarding" usually translates as "not boarding". But I hurried to the gate just in case – to find a scrum of passengers going nowhere. While I waited, two announcements caught my ear.
One reproached the unfortunate passengers who had just discovered they were going to experience a flight-free Sunday: some had hoped to fly to Edinburgh, others to Naples, but they failed to negotiate the airport labyrinth before the gates had closed. "Report immediately to gate 18 for transport back to the terminal or you will be waiting here even longer," a disembodied voice warned.
The other was for the flight to Bilbao, announcing a delay of an hour. The biggest city in the Basque Country is accessible in a couple of hours once the flight departs, but having tried both, the 36-hour surface version is far preferable. The Pride of Bilbao may not be the most modern ferry in Europe, but she is comfortable enough – and the two-night voyage provides relaxation, indulgence and excitement in whatever proportions you choose. The average no-frills flight does not offer that choice.
The electronic map aboard the ship shows the route in both directions as virtually identical, yet they are very different experiences. Leaving Portsmouth after dark, the ship slides into the busy shipping lanes of the English Channel and steers west-south-west for the pointy bit at the end of Brittany. The on-board catering ranges from a defiantly proletarian self-service to a restaurant branded as Langan's Brasserie, and it is easy to find a quiet corner of a bar for a nightcap.
When you awake (in your cabin, silly, not the bar) the vessel is likely to be near the tip of the Breton peninsula, where she turns a full right-angle to head south-south-east across the Bay of Biscay towards the Basque Country.
For anyone with an interest in sea life, this is where the fun starts. A naturalist is on board and on hand to spot the marine mammals who converge on the bay, and shrieks go up from the assembled passengers whenever whales or dolphins are sighted. In between times, you learn about the lives of the cetaceans – and the role that a regular ferry can play in researching the creatures.
Make sure you are up in good time on the second morning for the triumphant arrival on Spain's north coast. At about the time that mobile phones reawaken with a cacophony of bleeps, trills and gongs after their day-and-a-half-of slumber, the shoreline hoves into view: thrillingly corrugated, with a green ridge rasping beyond it melting into the (not-infrequent) mists.
Gradually the deep inlet leading to Bilbao takes shape – and only at this stage do a few poorly researched passengers realise that the ferry stops short of the city proper. She should really be named Pride of Santurzi, since that is the name of the dockland suburb where the voyage ends. No disappointment necessary: foot passengers can hop on the fast and frequent train direct to the heart of the city, perhaps pausing to admire the gigantic transporter bridge that commands the skyline. Meanwhile drivers who want to set the controls for the heart of sunny, ie. southern, Spain, can easily access the autopista network. Now, the neat thing about Bilbao is that there are no wrong answers in terms of onward direction: due west takes you into lovely Cantabria, going east puts you amid the Pyrenees in no time.
In between are three other viable vectors; south-west, for León and, beyond it, Extremadura; south, into the Rioja; and, south-east to Zaragoza – still with three weeks in its role as Expo 2008 venue – and beyond to the Mediterranean. And, when you reach ports such as Barcelona and Denia, you can carry on flightlessly flitting across Europe. If the ferry to Italy does not appeal, how about a (relatively) short hop to the Balearics? Palma airport may be one of the very busiest in Europe, with millions touching down in August alone – but you will have gone the pretty way.
Coming back on the long haul from Bilbao, you will have an equally attractive journey as outbound, just different. The voyage north is faster, and begins at lunchtime. This means that around 24 hours later you have a fascinating approach to Portsmouth along the south side of the Isle of Wight, then swinging around into the Solent and a dramatic arrival back to mainland Britain. And, unlike in Stansted, you will not be hanging around waiting for your luggage.
Simon Calder paid £108 outbound and £89 inbound, including cabin accommodation, between Portsmouth and Bilbao on P&O Ferries (08716 646464; www.poferries.com)