A spokesman for the Border Force said the cocaine had an estimated street value of 20 million pounds ($31 million), The Guardian reported Friday. It was discovered during an intensive search after the yacht was towed to Newlyn in Cornwall.
The yacht, the Windrose, was registered in the Netherlands, authorities said, and was believed to be heading from Portugal to Falmouth, Cornwall. It was towed to St. Mary's in the Scillies Monday after the man on board signaled he was having problems.
The man, a Dutch national described as being in his 60s, climbed up the mast 2 hours after Border Force officers arrived Monday evening and then plunged 40 feet to the dock.
The Isles of Scilly, a group of five inhabited islands and many smaller islands and rocks, lie southwest of Cornwall. The waters around the islands are notoriously difficult.