I saw a young man drive a nice new boat from the ramp, across the river into the current and anchor. This was a deep sided jon boat with a 25hp motor. The anchor pulled the bow under and it sank in under a second.
There is no time for a knife, or undoing the line. He was swimming before he could stand straight up.
NEVER ANCHOR IN CURRENT.
He was a newly wed, and it was his father-in-law's new boat....talk about starting off wrong.