Harbour area too far for disabled

I WAS with my camera club, Croft Camera Club, and I decided to visit the harbour area of Blyth to take photos of the yachts etc.

I am disabled and have my blue badge as I cannot walk very far.

I got to the entrance and was told you are not allowed to enter with the vehicle but you can park by the caravan storage area and walk down.

The distance from there to the pier is, I guess, about one mile.

How is a disabled person to enjoy the harbour area?

Can anyone tell me why you are not allowed to view the yachts and the old buildings that are around that area. Is it private property?