Yep, might be a good idea, I can see where Satnav is coming from, you can attach 10 chains, shackles and turnbuckles, but in reality, all that secures the lot is a cheap (possibly Chinese) stainless ring, with a 8-10mm bolt and nut on the inside, that said, if you hit the brakes in an emergency, and the winch post snaps off, a turnbuckle is not likely to stop a couple of tonne of boat once it gets moving! but, having nothing at all has got to be worse....