I have just added this to the map of places to fly your drone at Drone Scene:
Land owner permission not required.
At time of flight (early morning) no activity at marina so no permission needed. If you wanted to fly during busy times then I believe asking Harbour Master would be appropriate . Plenty of parking on nearby roads, coffee shops and pub on site, nice pastries from 1 shop. Coastal scenery just along shoreline within 200 yards . Lifeboat station also here.
The originator declared that this location was not inside a Flight Restriction Zone at the time of being flown on 17/08/2022. It remains the responsibility of any pilot to check for any changes before flying at the same location.