LEWISTON – A Bates College professor is boning up on his knowledge about Norway and its iconic fjords before a 10-day cruise with Garrison Keillor.

Dyk Eusden, a geology professor at Bates College, teaches a “Geology of the Maine Coast by Sea Kayak” class in May; through that Eusden met naturalist Natalie Springuel from College of the Atlantic. Springuel already was affiliated with the cruise and extended the offer to him to come aboard over the winter.

“It’s a place I’ve always wanted to go because the geology is so similar to what I study here. My reaction was, ‘Let’s go,”‘ said Eusden.

“Prairie Home Companion” Cruise Norway 2007, which begins on July 13, features Keillor, host of National Public Radio’s “Prairie Home Companion,” as well as the rest of the cast and musicians from the weekly radio show.

Eusden, Springuel and her husband, Rich, all from Maine, are the only three U.S. guides with the cruise. Another husband-wife team studying in Norway will join them.

He and the other naturalists – each with a particular niche – will give lectures on board, several 5 a.m. “naturalists on deck” talks, lead excursions onshore and write for the daily shipboard newsletter, The Ballast. On Eusden’s itinerary: walking through, and across, a glacier.

Eusden was already a “Prairie Home Companion” fan, and the boat’s bound to be teeming with National Public Radio listeners. He figures they’re going to be pretty inquisitive. They’ve probably studied up themselves before the cruise.

“My biggest fear is sort of a fun fear,” he said. “When I ask are there any questions, they’re just going to go wild.”