Outlander: How those ship scenes were shot 

But sticking Caitriona Balfe and Sam Heughan on a ship in the middle of the Indian Ocean isn’t feasible. That’s what made filming

at Cape Town Studios in South Africa so ideal: Practical ships already existed because that’s where Starz shot

. And there was more than enough room to create a whole new Jamaican world for the final five episodes of season 3.

All they needed was the appearance of an ocean. That’s where the green-screen technology came in — massive partitions held up by cranes that make the appearance of water around that “bucket of sh—e” possible.

],” executive producer Matthew B. Roberts tells EW. “I think there was 104 pages, and 6 pages are on land. When I first did the tally, a little aneurysm started in my head. I was like, I don’t know how we’re gonna do it. That’s just so much on the water, and we want to do it great. But it just so happened that on the same network, a drama with ships! Can we use ’em? Is it okay? Do we have to revamp ’em? And it ended up working out perfectly, timing-wise. The transition really didn’t take as long as you might think to move continents, hemispheres, time zones, everything you can think of.”

EW obtained this exclusive video and behind-the-scenes shots that demonstrate how those soggy scenes were executed.

“This year was much heavier in visual effects than we’ve ever had,” admits Roberts. “Every time you look this way or that way, you have to see ocean, so we need visual effects.”

The Artemis has short gunnels (or sides), which required heavy use of special effects. “We knew in these episodes that we were going to have to direct a large portion of our visual effects,” says Roberts. “The difference between the Porpoise and the Artemis is the gunnels. When you are on Porpoise, the gunnels are high. So if you are standing next to them, you don’t see the water. We get a free shot. But when you are on the Artemis, the gunnels are low, so every time you look out you see water. Those aren’t free, so that’s where the green screens come in.”

Massive green screens flank the Artemis, which was dolled up especially for

’cause I didn’t want to repeat anything,” says Roberts.

That’s a mighty tall crane, or two, or six. “Normally at a shoot, we get a crane out for a day,” explains Roberts. “We had 14 to 15 cranes every day. It was crazy.”

The production used gimbals to make it seem like the ships were rocking. “We would have to stop because there’s usually 40 to 50 people on [the ship] and people get seasick. I get seasick, even when we were doing the tests on the Artemis, which actually does go from 10 degrees to 10 degrees. At first everybody up there was going, ‘Oh, this is great.’ Then about five seconds later, we were like, ‘This is not so great.’”

The resulting scenes aboard the ships continue to amaze Roberts. “You know, there was no water for miles. Even seeing this and how it’s done and built and looking at mock-ups, I’m still amazed. It’s truly movie magic.”

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Ruven Afanador for EW; OUTLANDER TYPE BY LUKE LUCAS