Rescue and safety knives come in many forms and it is not a new invention. Swiss Army Knives are very good safety and rescue knives because they are quality made. Versatile SAKs with several functions
can increase every aspect of what the complete philosophy for safety is about.
Single blade options with plain, wavy or combination edges influence all the factors. On the pictures today
you see a well-used Victorinox knife I have used for years on the water in salt environments and it is still going strong. The other knife is made by a maker I have not researched yet. The design and construction I have seen several of over the years. It is
made with large pieces of cork so it will float. This is a design that has been used for a lot of different applications over the years. Examples are for fishing, life-vests, and other safety applications.
It is educating because it is a safety factor on the water to not drop you blades so it will disappear to the bottom. If you drop your blades in a situation you may be in trouble. I have restored the cork blade and sharpened it. It is a low cost knife
with questionable quality. The blade is very thin and it is flexible so it can reach tight places. Never the less I am very sure a person would be very glad to have it in an emergency.
carry system you use for your blades influence the safety. It should be carried in a pouch or in a pocket that is easy to reach all the time. A lanyard can have a loop for the hand so you will not drop it. It requires some training to be comfortable with safety.
The cork knives i have seen with different blade designs and it also got a lanyard hole.