we are going to the dunes on 13th april. we were thinking of going to angel falls, but will there be any water falling at this time of year? also we are confused about what money to take. some say usd, others say bolivars. if we take some bolivars to be going on with, and the rest in usd and usd travellers cheques where can we change it up? do they do it in the hotel or would we have to get a taxi into town? and one last question---can i sunbathe topless?