The Edge of Time oleh Dan Feltham

A grieving widower decides to take his 18-year old twin daughters and other family members on a sailboat cruise to the South Pacific. They visit the Marquesas Islands and then on the way to Tahiti, are suddenly hit by a mysterious storm. The merging of a rumored Mayan doomsday prediction, a unique date, time and set of mid ocean coordinates all result in a time warp back 200 years. They reach O'Taheiti in the year 1812 and are welcomed and entranced by the local islanders. They are individually torn between remaining with new friends on the island or attempting the unknowns of a return to present time. Love affairs and black pearls complicate matters. The story is a combination of sailing, time travel, history, fantasy, and South Seas romance. Come aboard and enjoy the trip. You may want to share their adventure, if only in the reading.