Maybe you should try an elderly shower seat. They made to withstand a lot of use and don't fall apart. Most are adjustable height from 14" to 21", made with or without a backrest. They are designed to be used wet so they are made good and have a lifetime warranty. Lightweight alu legs and a plastic seat with a 350 lbs weight capacity. The Lumex bath seat comes in different colors, grey, olive green, blue steel, chocolate. They are a no tool assembly, so if you had to carry it far, you can take it apart and put it in a pillow case or a small bag with a piece of rope for over your shoulder? They are built solid and don't fall apart like a lot of the junk made today.
WI Youth & LTH Mentor
Dodge Co. NWTF