A paddler who is carrying ropes or intending on using ropes should always have a knife to hand. This allows the quick release should the ropes become entangled or trapped. An ideal paddling knife should be able to opened and operated with a single hand. The knife should always be a lock knife so it does not close back down on your hand in dynamic conditions.
The Wenger Ranger 51 has a straight edge steel blade, with a safety lock system when deployed. It is designed for one handed opening and operational. It has a keyring so it can be attached to your buoyancy aid.