This is only an estuaral river, meaning it is served by the sea up to the point where The River Gipping discharges its fresh water into The Orwell at Ipswich. The two are quite separate rivers but some regard them as one river.
At the point of Pipers Vale on the North bank of the Orwell just outside Ipswich it is possible to walk this distance to Trinity Quay at Felixstowe Docks but care must be taken if walking along the shore line on an incoming tide.
A few short years ago visiting yachtsmen/sailors voted The River Orwell the second best river in England. Only the River Dart in Devon beat it in to first place. I have no argument with this as I have sailed the Dart on a few occasions.
But for me to have this River on my doorstep is an absolute bonus