My mainlines are strictly snaps and my leaders off of any divers be they are dipsy's or jets have enough swivels on them to stop line twist as for cranks work just fine off the mainline with the snaps, but if you have a swivel and snap that to me seems fine and I have been told it makes little difference to their action of the cranks. I have a friend who only uses snap swivels on everything. Also, my preference is to use only the duo-lock snaps because of the rounded/circular end. As a convenience for myself I pre-make leaders with a swivel at one end a duo-lock snap at the other end. I hate to tie things up on a rocking boat.

Gene