Polygons appear to flicker or flash on distant objects. My take is the drawing order messing up? Sometimes it switches between the backside and forward facing polygons. They are different colors so it looks like flashing.
movie of ship
Someone said a camera issue not a model issue?
Sounds like a z-buffer precision issue. Make sure the camera near clip plane is as large as possible and the far clip plane is as small as possible.
There is an Antialiasing option in Unity’s Post Processing component select Temporal Anti-aliasing there and it will solve the problem mostly.