I am a stranger to this area and need to find a very special place to have a wedding breakfast for 6 people on 2nd March in the afternoon - a place of historic interest maybe - or by the river - or up/down the river being transported on the river in a cruiser .Can you help me please?
You could try Bankside Restaurant (http://www.toptable.co.uk/Details.cfm?rcode=A806) they host weddings and the food is quite reasonable. There isn't a river view as the restaurant is actually below ground, but it's very near to the Tate Modern and you could always take a walk afterwards.
If you really want a riverview, then the OXO Tower can't be beaten - although pricey and can be a little pretentious. If you ask nicely though they might reserve a table outside or river view if you tell them it's a wedding breakfast.