Participants at this weekend’s Baltimore-based Rockin The Harbor Poker will have one of the marine world’s softest spoken and gracious powerboat designers walking and boating among them. That’s because the Maryland event is the second “summer tour” stop this year for Mystic Powerboats founder John Cosker and his wife, Robin. As they did last weekend at the Dam Boat Run on Lake Murray in South Carolina, they’ll be running the DeLand, Fla., company’s demo C4000 catamaran all summer.
The Coskers have done summer event-tours before, that’s nothing new for them. What is new, however, is that they’re doing this one to showcase and promote latest-generation C4000 cat, which prior to the release of Mercury Racing 500R outboards needed a bit more power. Twin supercharged, V-8 outboards—plus a move to some carbon fiber construction and a few design tweaks—was all it needed to come alive.
“It’s been a few years since we did a summer tour,” Cosker explained. “And this be the first one with the cat. We did one with the M5200 and one with the M4200 center consoles.”
Additional Mystic summer stops will include the Boyne Thunder Poker Run in Michigan, followed by Upstate New York’s 1,000 Islands Charity Poker Run, which is a Cosker family favorite. The couple will take a break, meaning they’ll run the 40-footer in Cosker’s former Northeast home-waters, before hauling the C4000 for the late-August Lake of the Ozarks Shootout Week in Central Missouri. The following month, they’ll head for the Lake Powell Challenge in Utah.
Though the tour officially kicked off with third annual Lake Murray happening, the C4000 has been Cosker’s favored demo ride since late 2024. Since late-November, he has logged more than 100 hours in the catamaran.
“It’s funny, we sold six in one nine-week period this year,” said Cosker, who currently is hauling the boat to this weekend’s event. “The push has been working.”