I take a lot of landscape photos, and am almost always shooting at ISO 64 with a tripod, and often with long exposures. With my D850, I have realized that to achieve the best results a tripod is very useful.
If I am shooting from a moving ship - at a distant subject with a wide-angle lens, I don't think the linear ship movement in its direction of travel will affect the picture that much - IF the ship isn't otherwise rocking or vibrating from the engines, etc. So my question is related to how much vibration, and other ship movement, should I expect? Will I need to go to high ISO