Can someone recommend a brand of fixed harness lines that don't swing around on a skinny boom (25mm diameter). The Chinook fixed 30 inch lines I've been using are good on a larger diameter boom, but they always seem to swing and I find myself inadvertently re-hooked in half way down a wave.

The boom is the same diameter as a Severne Enigma. Can someone using Severne lines on an Enigma confirm that they don't swing?