A yacht sank on its mooring in Cass Bay on Monday night.

An Environment Canterbury spokesperson said the Harbourmaster was aware of the incident.

Salvage attempts were made, but had to be abandoned due to worsening conditions that made it too dangerous for the crew to continue.

There was a small amount of diesel aboard the yacht, less than 20 litres, but no spillage has been observed so far, the Environment Canterbury spokesperson said.

“You might notice small amounts of debris washing up on Cass Bay in the coming days. Salvage operations will resume when conditions are safe.”