This thread is as crazy as they get.
You either take a holiday with a civvy or you take a punting holiday.
Not really. The OP just sounds like he is unable to know his own flippin mind. She has already started to control him. Either she wants to fuck him or else sees him as some sort of harmless substitute boyfriend/companion who will toddle around after her so she can imagine being feminine with nice male attentuin but without the sex. With such a pussy-whipped acquiescent attitude (at least it appears that way) no wonder the poor bloke prefers sex with prossies. And if she doesn't want to fuck him, she needs a straight-looking gay male friend.
Now to look at this another way, how would you feel if you fancied someone, they agreed (without any clear indication of bedding arrangements) that they'd like to go on holiday with you, you got all excited and thinking up nice things to do together and 'bond', and all the time the two-faced little fuck is looking at you as extra baggage?
Unless you want a totally shit time, then man up a bit. Decide either you genuinely like her as a friend and want to have a genuine shot at enjoying her company or decide to try and bed her. If she's already spent money on a holiday with you when you don't want to be with her, then you have not been very decent. Same as if it was a male friend who assumed you wanted to hang out together and you really intended to fuck off and look for whores or go for a wank twice a day. Don't turn someone who is well-disposed (even if a wee bit manipulative) into an enemy. Get a copy of Lonely Planet or something and take the frigging lead on "things to do together." You might even find you develop a mutual agreement on "what if one of us wants to do their own thing one night?" Or, "What if one of us finds someone they fancy?
I can tell you one thing: I wouldn't want to go on fucking holiday with you mate with that sort of attitude, punting or not. Punting, however much fun, is a sideline in life: not a career. It sounds like you've screwed up but just learn from the mistake and make a positive experience out of it while there's still time!