I have just added this to the map of places to fly your drone at Drone Scene:
Land owner permission requirements unknown.
I visited this location early one Sundtay morning (07:00) at low tide and parked on the slipway itself. I doubt that it will be possible to fly from here once the world has woken up!
It is in the coastal scenery category but could equally fit into several other slots - to the north are the buildings of Portsmouth's Historic Dockyard and the preserved ships - HMS Warrior, HMS Victory and HMS Driftwood - the Mary Rose.
I was there to photograph the railway station but the modern buildings of Gunwharf Quays and the 170 metre Spinnaker Tower are to the south with the Wightlink ferry and the buildings of Old Portsmouth and Spice Island further south and within VLOS - if your aircraft is big enough.
I was there for over half an hour with no-one taking any notice.
Be aware that there is a High-Intensity Radio Transmission Area on the chart just to the north. I encountered no problems and suspect that the area tends to be active 9-5 weekdays. But make sure you have your home point established before flying out over the water!
The originator declared that this location was not inside a Flight Restriction Zone at the time of being flown on 02/08/2020. It remains the responsibility of any pilot to check for any changes before flying at the same location.