You probably could have a candle set up. Just remember how windy it gets in the countries when you are off of the lake. As I was told, as long as you are not superstitous if it blows out..... We are renting a hurricane shade to protect the flame, and in the video editing, if it blows out they can "relight" it. We are also back behind the UK so it should be ok. Another suggestion that my EM made was to do the sand ceremony.
Just another option.