I don't think it's redundant, as the reader might not know that it would rarely roll from front to back. It's surely no more redundant that "bobbing up and down," which is definitely idiomatic. I'd say there's a difference between emphasis and redundancy.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
AvangiI don't think it's redundant, as the reader might not know that it would rarely roll from front to back.It's surely no more redundant that "bobbing up and down," which is definitely idiomatic.I'd say there's a difference between emphasis and redundancy.I thought "roll" means tilting to one side? So if a ship rolls, i
SheltieBitesI thought "roll" means tilting to one side? So if a ship rolls, it could be that its bow dips and stern rises?If it's a large ship, an experienced person would assume it's rolling from side to side, if there's no further context.