The shackle-opener (or shackle key) is used to open and tighten screw-pin shackles used on marine rigging. Available on some marine focused 111mm Victorinox knives, the shackle-opener is combined with a marlin spike, that is used to splice rope, untie knots, and other rope work.
- Marlin Spike - A different marlin spike/sacking-needle tool
- Large Marlin Spike - A more recent thick marlin spike/shackle-opener
Wenger has several nautical orientated 130mm models in the Alinghi Ranger Series that include a shacke-opener/marlinspike tool, that is very similar to the Victorinox shackle-opener. The Wenger tool includes both inch and cm scale marking on one side of the tool.