I have just added this to the map of places to fly your drone at Drone Scene:
Land owner permission not required.
Spitbank Fort Southsea I parked in the local parking area. There are lots of free parking however you are limited to two hours.
The originator declared that this location was not inside a Flight Restriction Zone at the time of being flown on 11/07/2021. It remains the responsibility of any pilot to check for any changes before flying at the same location.