For most Wagnerian bass-baritones it's considered first port-of-call.

The Flying Dutchman is leaner, cleaner and frankly a great deal shorter than the gargantuan music dramas Wagner wrote later in life; little wonder that its title role, the eerily-unnamed Dutchman, has launched the career of many a future Hans Sachs or Wotan. But when his ghostly ship glides into view at the Theatre Royal tonight in Scottish Opera's new production of The Flying Dutchman, Peteris Eglitis will be making a much overdue debut. He's already weathered Die Meistersinger von Nürnberg and Lohengrin; his Wotan has presided over many a Ring cycle; but for one reason or another (schedule clashes, mostly) he's not had the chance to sing The Dutchman – until now.

Earlier this week Eglitis talked me through what it takes to learn a major Wagner role from scratch. "Sure, it's his shortest opera, but no Wagner hero is an easy sing," he says, speaking voice a rich bass-baritone, American accent tinged with Latvian roots. "I've taken a full year to learn The Dutchman, and would describe the process as a bit like whittling a big chunk of wood. You start with masses of notes and have to envisage what you ultimately want it to become. Then you whittle it down finer and finer until you get there – hopefully in time for opening night."

In terms of vocal technique it's no walk in the park, he says, with extreme highs and extreme lows often in quick succession. Wagner's orchestration is typically surging and thick, intended for opera houses where the pit is buried deep under the stage and voices are bred on a Herculean scale. Although Eglitis won't need quite the same stamina as he might for the Ring, he'll still have to summon the decibels. "It's not all loud, though," he points out. "People often assume that all Wagner is flat-out all of the time, but he wrote a lot of pianissimo passages too, and these are some of the most magical. It's been great to hear Francesco Corti [Scottish Opera's music director] really focusing on these passages with the orchestra over the past week."

Born in the United States to Latvian parents, Eglitis's vocal heft and colour first caught the opera world's attention in 2001 when he sang Wotan in Die Walküre at Dresden State Opera. Having lived some of Wagner's most weighty roles for more than a decade since, how does he feel about the music of The Flying Dutchman? "It's easy to catch glimpses of the harmonic language, maybe the types of dissonance, maybe the flavour of certain emotions, that develop in the later operas," he says. "And it's particularly easy to see the influences Wagner inherited from Italian opera in the Dutchman's forms and melodies. These kind of smooth lines aren't always associated with the hard consonants of the German language, but Wagner understood innately how to write for voices: The Dutchman is an excellent reminder that with any Wagner, late or early, the vocal melodies need real line and direction."

Scottish Opera's production transports the legend of the Flying Dutchman – cursed to roam the seven seas for all eternity unless he finds the love of a faithful woman – to the north-east oil coast of Scotland circa 1972. Director Harry Fehr hopes that the audience will to relate to the setting and thus to the characters. But is 1970s Aberdeenshire a time and place that Eglitis can easily conjure up?

Yes and no, he says. Although he was raised and trained in the US, Eglitis now lives with his Latvian wife and three young children near the Baltic port town of Liepaja. His family history in the area dates back 300 years, and it's where his grandparents were forced to leave around the time of the Second World War. "Living in Latvia feels like the right thing to do," he says, "to go back and pick up where they left off." He describes himself as a "backyard farmer": he grows his own veg, fishes for northern pike and loves the peaceful scenery of the Baltic forests and lakes.

And, crucially, he understands the sea and the mentality of small coastal communities. "Members of my family are seamen. My uncle is a tugboat captain and has always regaled me with stories of life out at sea. They're tough guys; they observe before they speak. My impression is that they also tend to have a deep sense of longing, either for home when they're at sea or for the open waters when they're at home. I don't know exactly what it was like in Aberdeenshire in the 1970s, but I can relate to the eternal longing that torments The Dutchman's soul."

Eglitis says he's glad to be coming to the role at this stage in his career: a lot of singers tackle it too early, he says, and it needs "more force than a young singer can bring to it. The male voice, especially the bass-baritone voice, gains a certain amount of strength and metal that simply can't develop by 30." Now 44, he says that, like looking at photos and realising how slim he was back then, he listens to recordings he made even just a few years ago and hears a boyish sound.

"The opera business is obsessed with finding new talents. It makes for an exciting turnover of fresh voices, but it also promotes a use-and-discard attitude. The best voices are like the best wines. They take time to mature. Of course you have to take proper care of them: the room temperature needs to be right, the bottles need to be turned every now and again. In that sense it's the singers who come back to their roles every couple of years who become the real masters. With Wagner, it's always the long game."

The Flying Dutchman opens at the Theatre Royal, Glasgow, tonight.