There's not much to go on from the sketch but I have chosen to make shoes and buoyant poles by taking many six-inch pig bladders filled with air and wrapped in leather parcels using thongs and string, and then bound to paddles with leather straps and buckles to hold the whole contraption close to the foot.
As much as possible I have stayed true to the dimensioning shown in the sketch. By this I am sure to do what is asked of me without daring to change the design of the master. However, while I found that twenty bladders were enough to keep a person afloat they did not allow for the shifting of weight from one foot to the other. In my opinion so many bladders and boards are needed to make this idea work that one would be better to make a small boat… And come out of the effort much dryer!
If I am asked to do anymore of these madcap projects I will hope that I am to turn us into cats. By this we can expect to eat tidbits of fish, and spend our evenings cosily in front of the glowing embers of a fire.