Here is a goal: Check if flotation devices are leak proof before mounting.

How would you accomplish this goal?
Fill the flotation devices with air one at at time , take a spray bottle and mix soap and water together until water is sudsy, carefully start spraying your first flotation device with the mixture looking for bubbles being bade by air being released, check entire area of the flotation device, do each device the same way circling bad area with a colored maker.