If you have an old inflatable mattress, consisting of several independent sections, it is easy to adapt as life jacket for boating. You will have to sacrifice one of the middle sections, making it T-shaped hole for threading of the head. To fix the other slightly inflated section around the torso using the waist belt and extra lacing.
Recommend to read
“SINGING” INSTRUMENTS
"What to replace the gauge?" — this question often arose during the meeting with an interesting measurement scheme. Ohmmeter, voltmeter, test transistors — these devices are difficult to...
“ELECTRONIC” CULTIVATOR
The idea of creating a mechanical assistant for garden cultivation came to me a long time ago. I looked through relevant issues of the “Modelist-Constructor” magazine with descriptions of...