Mast weight and water inside

This summer has been quite windy and a few days have been really "interesting" getting the mast up/down with the sail on. It occurs to me that my bare mast seems heavy, and while that may just be a need to get stronger, I do think it has some water in it. How do I check/remove the water? Any good way? I see that each section is plugged inside (presumably for some buoyancy during capsize?), but I don't see any good way of removing them. And the one time I  tried to remove one of the plastic ones, I had to buy a new one....

Is there a spec weight for the mast or sections? If there's only a little in there, maybe I won't bother.