If you have Aire thwarts they usually have straps and d rings that lace into the floor webbing. If you use carabiners make sure that they are locking as to avoid accidental clips to footwear and entrapment issues. I would recommend putting a few of the oval links (like for connecting chain) that you can get at the hardware store and put them where you will lace in the thwart to the floor to reduce wear on the floor lacing.