Hi Heather! Thanks for reaching out. It is indeed a tough choice, and at the end of the day, it comes down to what is more comfortable for you. Both tours offer great views of the city - during the day you see the buildings in all their detail in the sunlight, and at night, the dark sky is lit up by all of the buildings and the water reflects much of the light, which has a really nice effect. I definitely understand the nervousness around dark water - many people experience that feeling. If you think that will make you so nervous that when you arrive, you would not want to go, or it will ruin your experience because you are on edge the whole time, then I would not suggest that tour. However, there is significantly less boat traffic at night, which may cut down on the amount of wake on the river. Some people are also uncomfortable with choppier water and boat traffic. If it makes you feel better, the water is not very clear during the day, either, and there are no dangerous creatures that live in the river. You would be wearing a jacket. Our boats are very stable, especially doubles - and only 10 boats flipped last year (less than 1 in 700). It is very unlikely you would end up in the water. I personally think the nighttime tours are a more unique experience, and they focus on gangsters instead of architecture and the developmental history of the city, which can be more entertaining to some. Let me know if you have any other questions! Thanks, Adam