Well, I can now answer my own question.. NO there isn't :-(
I managed a couple of glimpses into Grimsby Docks and that was about it, everywhere else is "off limits". Cleethorps is the only place to view any movements but the shipping is too far away for photography.
The north side is just the same although I didn't venture past Hull, there are vantage points further on at Paull & Spurn Point. I did read somewhere that there was public access to the locks in Hull but I couldn't see a way in, can anyone verify this and perhaps name the road for future reference.
Regards
Bob