During the day we stand watch, but, really, everyone on top is keeping an eye out. We don’t run radar, but rely on AIS and the Eyeball Mk I.
At night, it’s a different story. It’s dark, distances are hard to judge, some smaller fishing boats and such don’t run AIS, or even lights, there are some stationary things (I think I caught a platform of sorts above the water one night watch).
So we rely on AIS, Doppler radar, and thermal camera. We put them all up on one display and our speed is such you don’t need to stare at it continuously, but once in a while.