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
SLIPWAY FOR ROOM
The one who animaetsya room with model airplanes knows what a difficult job the installation of the stretch marks. But they stiffen the easiest transparent planes, and even a small error...
SCREW ON THE CONTROL
When developing propeller systems snowmobiles, trikes, aircraft and model aircraft designer is required to know the exact values of some parameters. And most importantly — the frequency...