It seems they did already so much to find him. From the Sussex Police. Honestly....I think they were to much focussed on the water angle.
"Specialist teams have carried out extensive searches of the area surrounding the pub and the Pells Pool area, which has been severely affected by flood water over the past few days.
Chief Inspector Sarah Godley said: “We have reviewed CCTV footage from a number of premises such as homes and businesses, and we are continuing to retrieve and review further footage as we attempt to find out what happened to Anthony. We hope this latest image of him may jog someone’s memory or help provide some new information about his disappearance.
“Our searches have included local officers, drones and the dog unit, and we have also been assisted by London Fire Brigade, East Sussex Fire and Rescue Service, the National Police Air Service helicopter, Sussex Search and Rescue and the Coastguard agency in our quest to locate Anthony.
“The area we have searched includes Pells Pool and Pellbrook Cut, as well as bins, street furniture, alleyways and dark areas.
“In addition to the local area, we have also extended our search of the River Ouse north towards Hamsey, and we will continue to search for Anthony until we get the answers his family are so desperately seeking. Seven days on, our priority remains to find him.
“A further search of the Pells Pool area and the river will be carried out over the weekend as the natural water level falls. The flood water has made our operation challenging, but we remain committed to finding Anthony.”