The Time Cave - Spanish Main

"The Time Cave - Spanish Main" is a rip-roaring, old-fashioned pirate adventure. Our heroes, Jack and Tom are mysteriously hurled back in time to the 18th Century Caribbean Sea, known as the Spanish Main, where they are kidnapped by murderous pirates who sail the seas looking for ships to plunder and rob. With no choice in the matter, they become part of the ship's crew under the command of the feared pirate Captain Edward Boyle.
The boys are befriended by teenage brother and sister, Jasper and Kate. They had been kidnapped a year earlier and held for ransom when sailing from England to Jamaica, where their father Sir James Bennett, a wealthy Englishman, owns a sugar plantation.
Together they make plans to escape but many dangers stand in their way, not least a bloody sea battle which almost costs them their lives. One terrifying adventure leads to another. Escape, pursuit and shipwreck, with Jack and Tom poised perilously between getting home and living the rest of their lives in the 18th Century.