Not sure how they work, I assume they hinge in operation, not just for storage? I can't see them being so effective hung off the side cleats of the boat, as there is very little up and down travel in that scenario, and I reckon the first foot or so of upwards travel will just open the plates without offering much resistance. They may work better on an outrigger, where the speed they sink is more important than the amount of "wasted" upwards travel before they bite. I'm quite crap at explaining this.