A Wightlink ferry is assisting with a medical emergency onboard a yacht in the Solent, Isle of Wight Radio understands.
Early reports suggest the cross-Solent operator's St Clare has stopped en route to Portsmouth, and is heading East towards the vessel.
A RIB has also approached the yacht, with a member of its crew boarding the yacht in order to offer assistance.
The Coastguard's search and rescue helicopter from Lee-on-Solent is currently hovering over the scene, and Gosport lifeboat is also present.
We've approached HM Coastguard for a comment.
*Updated
*Wightlink has confirmed its 10am Portsmouth to Fishbourne sailing diverted to assist the crew of a yacht.
The incident happened near North Sturbridge buoy, south of Spitbank Fort who had issued a Mayday message.
A spokesperson said:
"A crew member had been injured in an accident on board.
"On arrival, St Clare stood by to enable the warship HMS Severn and emergency services locate the yacht and to protect the vessels from north-westerly winds."