Photo for dating please - Thames boat trip.

[Gadget]

I was in two minds about pre or post WW2 - some of the women have pre-war hats on but it is mostly WI women and it could be post-war rationing so I'm an either or 

I do remember, as a toddler in the late 40s,  women wearing such clothes.

[Regorian]

And to me. Looks like 1930's earlier rather than later. hats look 1920's and early 1930's. Two boats, Mapledurham and Hampton Court (nearer). Salters Steamers I think. Now, where? Possibly Windsor, see bridge to Eton? on right, but could well be downstream as far as Hampton Court. Salters went upstream to Oxford as well. Clues perhaps for the ace sleuths.

Added: Looked at some of the riverfront pics. Hampton Court to Oxford, this looks like Windsor, ie river width, same view today would be different. Buildings redeveloped.     

[Treetotal]

Having had a closer look and comparing with some of my own photos I think it could be late 1930s. If it was early-mid 1930s I would expect to see some brimless cloche hats. Most of the ladies are older so wouldn't have been that up to date. I have attached a WW2 photo of my own of a ladies table top sale for the war effort for comparison.
Carol

[Regorian]

I see what you mean, my grandmother looked like them and died in 1953 at 75. It's not Windsor either. I will look at places upstream where Salters boats might have tied up. 

[Gadget]

They look very much like your photo, Carol 

[Top-of-the-hill]

   We seem to be tending back to pre-war now. For the river experts, as far as I can make out from the minutes, the 1947 trip went by coach to Richmond, presumably getting the boat there. Alternative was train to Hampton Court, but this was the pre-planning. Minutes were not written with this in mind!

[Gadget]

Is there anything at all on the back?

[Gadget]

Just adding this enlarged snip, including the ?2 men

Add - that front man loos a bit like Humphrey Bogart 

[Top-of-the-hill]

   Yes, the two men have baffled me a bit, perhaps they were interlopers! In fact the whole thing is a bit baffling. I think I am going to assume pre-war and leave it at that. Unfortunately no minute books for the 1930s, it has been suggested they went for salvage.
   Thanks for the suggestions.