No. From the Cobbl Home Page, select Explore Cobbl Boards at the top. This will take you to a Wall View of Public Cobbl Boards and then you can view and share these boards. If a public board permission is set to ‘Anyone Can View and Post’, then you can even post to this board. If a board displays Add Content icon, then you can post to it. Often time board owners put details on what they would like posted to their boards in the Branding Block.
You will also be able to see a specific board if the owner has share the Board Link with you and the board permission is set to ‘Anyone with Link’ can view and/or post.