OCEANSIDE — New “at-sea” entertainment has been added to the list of sport fishing and karaoke cruises. Theater on the Water hit the high seas off Oceanside Harbor on July 31, and will continue every Friday, Saturday and Sunday evening.

The concept of a mystery riverboat tour that uncovers clues, harbor history and introduces passengers to businesses around the harbor is the brainchild of Theater on the Water producer and promoter George Reh. “It’s based on the mystery walking tour of Brooklyn,” Reh said, adding that it gets people acquainted with harbor businesses as the mystery develops.

“I loved the combination of mystery and sightseeing,” Patti Marco of Encinitas said. “Looking at the city of Oceanside, I got a new view of it from the boat.”

The Theater on the Water production, “The Oceanside Bell,” begins dockside aboard ship, cruises out to the pier and makes stops at restaurants on the way back to pick up complementary eats and “clues” to solve the mystery.

The whole concept of gathering clues, stopping at restaurants and looking for a way to lift the boat’s curse, is clever, Kara Corona of Carlsbad said.

“It’s a great concept and great for (harbor) businesses,” Mike Seymour of Del Dios said.

The narrative by ship captain Bob Kendrick mixes historical facts with fiction.

One fact is that the out of place Oceanside Belle riverboat, which is the stage for the adventure, has been sitting idle in Oceanside Harbor for some time and has been know to emanate “odd” noises. Kendrick, who is also a playwright, said there have been “hauntings” since he teamed up with Reh to write the script. “The things we’ve experienced since we’ve started with this are incredible,” Kendrick said. He said he went through four tape recorders preparing for the performance.

Fiction comes in the form of the four clues left harborside by the four prospective buyers of the boat to explain the haunting and how “the curse” can be lifted from the boat. A hint for those trying to solve the mystery is that the answer may be right onboard.

Kendrick is the primary writer of the mystery. His career has been 30 years on stage and five years on the sea. “I’ve been involved in showbiz most of my life,” Kendrick said.

Kendrick said the difference with performing at sea is the unpredictability of the natural environment. “The sea is always dynamic in a different way,” Kendrick said.“The animals and conditions change the character and cadence of the narration.