Now the tide's lower, we can see the end of the slipway we looked at earlier poking out from the Somerset side. According this article from the Bristol & Avon
Family History Society:
In 1793 the ferry was identified as being used by many passengers to "cross the river at Rownham ferry and walk to the sweet and wholesome village of Ashton to eat strawberries and cream"
GPS Coordinates:
51.44765, -2.62547
Location: Hotwells