Fear What Isn't Seen

I've never encountered fog this thick.
At 6:45 in the morning I was forced to pull up anchor to move for a tug and barge heading up river. The fishermen were out of the way but we were not. I had to trust the instruments completely, dodging into the shallows with only minutes to spare after the first horn echoed from the mist. I could see maybe 100 feet.
I would prefer less exciting mornings.