Standing aboard the wind-swept deck of the Pilgrim, a replica of a 19th-Century ship, the young sailors snapped to attention Tuesday afternoon as the surly first mate demonstrated the proper way to coil a rope.

"Clockwise! That's not clockwise," Bill Dempsey, the first mate, growled as he instructed his crew on how sailors did their jobs 160 years ago.

Dempsey's 29 crew members, all fifth-grade students from Clegg Elementary School in Westminster, boarded the ship Pilgrim as part of a "living history" lesson offered by the Orange County Marine Institute in Dana Point. The 18-hour adventure, which ends this morning, is part of a program aimed at teaching students about history through role playing. During their stay on the Pilgrim, a brig, with two square-rigged masts, students had to remain in character. They played sailors living on a ship traveling in 1834 from Boston to what is now Dana Point.

Dempsey, 42, an instructor for the institute, took on the role as the ship's first mate and disciplinarian, responsible for making sure the crew members did their jobs to perfection. As part of his role-playing, he alternately instructed, berated and praised everyone on board, including students, parents, teachers and institute workers, all of whom were assigned roles to play.

"What I expect from your lips is, 'Aye aye, Mr. Dempsey,' " the first mate told the sailors when they arrived. "You will never address me as 'sir.' There is only one sir on the brig and that is the captain. It is not possible to say 'sir' to the captain too many times."

Throughout the afternoon, Dempsey addressed the group as "men" or "lads," and pointed out that there were no female sailors back in the 1800s because women on ships were considered bad luck.

"Step lively, lads! Get the anchors out of your pants," he roared when the sailors moved too slowly.

To the grog-befuddled second mate, played by program coordinator, Ross Klingsberg, 27, Dempsey shouted, "My 92-year-old dead granny with a wooden leg who's 4-foot-2-inches tall can move faster than you."

The speech prompted some giggles, which Dempsey quickly quelled with renewed orders for the sailors to get moving.

In keeping with the setting, students and teachers were prohibited from wearing watches or sunglasses because such items were not worn by sailors of that period.