One of my favourite canal-side pubs is the Navigation on the Montgomery Canal in Maesbury Marsh, Shropshire. I'd imagine it has been a boaters' pub for a fair while.
Not sure how old it is, but the Narrow Boat on the Llangollen Canal near Ellesmere/Whittington (Bridge 5W) in Shropshire is a possible..?
The only other old canal-side pub that springs to mind in Shropshire (on still-navigable canals) is of course the Queen's Head, again on the Monty.
The Wharf at Shebdon I believe is no longer open (hasn't been converted to a house yet, but only a matter of time) but the Anchor nearby (at Bridge 42) is still going.