"I think this episode's going to be a real cracker," said Smith. "I'm a huge fan of pirates, so I was always very excited about this episode. Pirates are groovy, aren't they? It's swashbuckling at its best."
His co-star Darvill (Rory Williams) also praised the "ambitious" instalment, adding: "I think it's been realised in a really brilliant way. The little bits that I've seen just look amazing and it's taking the scale of Doctor Who right up."
Viewers can certainly expect some jolly fun on the high seas, but Gillan (Amy Pond) claimed that 'The Curse of the Black Spot' will also explore some darker themes.
"It is a big swashbuckling adventure," she conceded. "But they go into the story of a little boy stowaway and there's some sadness in there as well."
"We filmed from half four [in the afternoon] till half four in the morning, and we were all a bit nervous and apprehensive about the rain, but it just turned into giddy fun," he admitted.
"Cornwall felt like we were filming on a big movie set," added Darvill. "There were loads of people who had come down to watch, because they'd announced it on the radio, so it felt like we were doing an epic play!"
Gillan agreed: "Quite often we get a crowd if we're filming in a public place, but we've never had a crowd that big. They were just screaming constantly... but they weren't shouting horrible things. They were really excited!"
"Everyone was really nervous when I got a sword in my hand," laughed Gillan. "But actually I was fairly co-ordinated, which was a surprise to all of us."
"I did think she was going to take someone's eye out before we started," admitted Darvill. "But she approached it with control and dignity."
As part of her rescue attempt, Amy also takes a swing from the ship's rigging, as Gillan explained: "That was all me! It was really scary at first, and then I just loved it. I rehearsed it loads, when I didn't need to, because I enjoyed it that much!"
There's still plenty of room for character in this action extravaganza though, as Smith was keen to make clear, praising Hugh Bonneville's "wonderful" performance as Captain Avery.
"[The Doctor is] kind of a pirate professor, on his own, travelling around and being clever," said the star. "That's why I think he and Hugh's character find a common ground eventually."
Overall, Smith seemed confident that Doctor Who fans will be satisfied with 'The Curse of the Black Spot', calling the episode a "real romp".
"There's swashbuckling, swords, ropes, pirates going 'Oo-ar' and a crazy Siren with a strange song," he said. "Only Doctor Who could make a pirate story like this!"
Doctor Who continues this Saturday on BBC One in the UK and BBC America in the US.
> Doctor Who: 'The Curse of the Black Spot' in pictures