‘You’ll see it in a minute, it’s just over this hill.”

I was in a car with Daniela and Eduardo, owners of a surf hotel, but instead of heading to the coast we were driving to a farm inland, near the town of Sagres at the south-western tip of Portugal.

Surf B&Bs and hostels have flourished along the Portuguese coast in recent years – journalist Veerle Helsen celebrates their laid back charm and cool design in her book Surf and Stay – but we were making our way through the countryside to the Truck Surf Hotel, which offers something different and not just because it was parked on a hillside surrounded by cows and donkeys. After three years of travelling the Portuguese and Moroccan coasts by campervan and showing friends around, Daniela and Eduardo decided they wanted to share the lifestyle with others, with the freedom to roam from beach to beach and seek out under the radar surf spots.

Photograph: Daniela Carneiro

The result of their dream was a 19-ton bunkhouse on wheels that can hit the road in search of the best waves. The lower floor has a foldable table, sofa, bathroom, shower and kitchen. Large windows and sliding glass doors let light flood in. A second storey, raised on hydraulic arms, houses five double rooms (sleeping a total of 10).

Loaded up and ready to go, the truck took us to remote João Vaz beach, a few miles east of Sagres. The forecast swell had yet to arrive, so we took the opportunity to paddle out on our boards to caves just south of the beach.

“Not many people know about these,” said Eduardo, as we clambered down the dusty path to the cove below. “But they’re fantastic.” He wasn’t wrong – we explored in and out of the caves that lined the cliff face – their sheltered, calm turquoise waters providing respite from the sea’s swell.

Back at the truck, we told stories over glasses of Portuguese beer as the evening breeze took the edge off the summer heat. Daniela and Eduardo used to surf competitively, and the truck bears (discreet) photographs of epic waves and a signed trophy with the words “Keep ripping mate” etched into it by professional longboarder Harley Ingleby. Daniela, who swapped her job as an environmental engineer in 2013 in favour of a life on the road, joined Eduardo in his dream to build a “moving hotel”. From designing to sourcing the truck, it has largely been a DIY project.

GoPro cameras are used to film surfing sessions and to help improve technique

The next day the wind picked up, though the swell was more suited to pros. We began to wonder whether the powerful Portuguese waves were beyond our ability. Not to worry, Eduardo said, he knew a spot west of Sagres that would be sheltered.

We arrived at Praia de Beliche, hidden in the crevices of the giant cliffs that line this coastline. Our steep walk down was rewarded by a sheltered stretch of sand bordered by 40-metre red cliffs on three sides.

“Let’s wait for the tide here,” said Eduardo, knowing that as it recedes the waves become more rideable. We napped and woke to the sound of waves breaking a lot further way. “Time to go in,” said Eduardo.

Photograph: Daniela Carneiro

Daniela and Eduardo offered tuition throughout the stay and joined us in the water to shout advice and encouragement over the breakers. Using GoPro cameras they filmed our group’s successes – or more often our fails. We spent evenings cringing at our attempts – but the videos did help us see what was going wrong. Our final evening found us surrounded by fellow surfers eating delicious freshly caught cod on the terrace at renowned Restaurante Carlos in Sagres. Nothing to cringe at on this occasion, just good vibes.

Leaving the farm behind us, we travelled through the Alentejo and Vicentina national park, past swathes of protected coastline, the high cliffs casting shadows across the unspoilt beaches below. We arrived at a campsite Praia de São Torpes, near Sines, overlooking the beach. It took no more than 10 minutes for the truck to go from road-ready to comfortable home.

I used the change of location to take a day off from the surf, and to explore an isolated, deep local reservoir in a pine woodland for a dip and a spot of fishing with Eduardo – for small fish we would barbecue for dinner. That evening we visited the Herdade do Cebolal vineyard, for a guided tour and a tasting of its red, Surfista – a merlot that was a great match for our cheese and meat sides.

Back at the truck, camp chairs out and beers open, we listened to the cicadas and breathed in the intense aroma of hibiscus flowers. We were tired after long days in the water, our muscles ached and our ears buzzed from the white water, so the truck became our relaxation pad helping restore us. We enjoyed cooking together, barbecuing, listening to music and watching our now-significant number of GoPro wipeouts. Morning yoga allowed us to stretch our aching muscles, too.

Surfing near Sines

It was at the end of the trip that my favourite surf session came around – at Praia de São Torpes. We parked up at the northern edge of the beach as most people were heading the other way. The industrial port of Sines – huge container ships sailing by in the distance – gleamed as we surfed empty lines. Rays of sunlight caught the crests of the green waves, the spray, our boards and the now-deserted beach beyond. The breakers were small and so consistent we rode wave after wave, going back for more until the sun sank into the horizon.

• A one-week Surf Experience trip with Truck Surf Hotel costs €758 B&B including all lessons, equipment and analysis. It also offers a week’s Surf Guiding to the best surf spots (excluding lessons & equipment), which costs €670