I want to build a small floating platform to hold a wireless water temperature unit and a battery/solar panel power supply. Less than 5 pounds plus the platform material (pressure treated wood?) Any thoughts on flotation? I don't want to use foam. Dock floats seem to be too big and overkill.

Hey Rob,

I would just make a simple PVC frame. As example, you could make a 2ft x 2ft frame out of 2 or 3 inch PVC pipe with elbows on the corners. The entrapped air will easily support your sensor. Estimate the cost at $25. To make life even easier, big box stores like Lowes, Home Depot, etc. sell pre-cut 2ft lengths of PVC in many diameters.