

I need you to do an incident meter reading at the same time of day adjusted for summer dates. You really don't know what the exposure value will be under these conditions, do you! Well I don't either. Do you know where the horizon will be in relation to their faces? No. Pushing your film one stop is really nothing to give you any confidence over. I would take control of this situation by presenting the risks and give a solution of a few flash shots with a try at natural light shots. The gently moving ship, the lack of room, the twilight (I guess) conditions are too, too difficult to guarantee results that attain a professional level. Clients can be demanding, and not know the danger they are leading themselves and you into. I wouldn't be pushed into a risking taking 'zone' on a wedding unless I had a back-up set of photos that were taken with flash.

You ask about strategy you ask about film and 'pushing it'.
