I hope that anyone onboard survives. If kitted out with diving gear they stand a chance. Here are the details from the BBC:
Coastguard alert over empty boat
Two lifeboat crews are urgently searching for boat passengers who they believe could be missing in the Solent.
A rigid inflatable was found washed up on the shores of Southampton Water at 0518 BST on Wednesday.
Solent Coastguard believe the boat had been occupied and it is feared its passengers may be overboard.
Coastguards said it is "very, very urgent" that its owners are traced. The 5m (16ft) craft had the words BMW Sub Aqua on the side.
Solent Coastguard watch manager told BBC News: "All indications were that there had been someone in the boat. This is very, very urgent."
He said a helicopter could not be sent to search until it was certain someone had gone missing.
Anyone with information about the boat is asked to call 02392 552 100.
The search has been called off as it had been stolen.
" Solent Coastguard put out an appeal to The police Marine Unit and has now discovered it was taken from a pontoon on the River Hamble and are asking anyone who was out on the Solent during the Trafalgar 200 celebrations yesterday, who may have seen the blue and orange craft, to contact them".