I suspect (another guess) that easily at least a 1/3 of the weight of the tower is the solid fiberglass top - and possibly Grady is quoting the weight of the boxes, too?
To make it a collapsible fixture... it would certainly be a neat project. You could figure out a way with a pulley system to lower and raise it - that would be the easiest part of this endevour. The biggest challenge is along the lines of what Fish mentioned - making sure it's secure when underway. A friend of mine has a collapsible wakeboard tower on his Mastercraft. Obviously a sports tower gets a tremendous load put onto it. The tower is HEAVY - the only reason I know that is, unfortunately, it's a manually collapsing tower and we need to lower it to get in to the garage... which means lowering to get in and then raising it again once it's out... every single time. The "joints" that are used where the legs come apart to allow it to pivot down are VERY secure. Once it's locked in, it's as solid as a tower that doesn't collapse. IT could get pricey to redesign your tower to be collapsible, but with some thought and $$$, I think it's doable.
