Mushroom mooring don't come much heavier than 1,000 lbs and 500 lbs is much more common. In my opinion, that just isn't enough weight to hold a larger boat in storm conditions. That is why I have a 3 ton granite block. The pic is Seaquestor this last monday during about a 30 knot easterly. This kind of pitching can yank a 500 lb mushroom off the bottom. My granite block mooring didn't move a bit. In fact, I doubt it even lifted much of the bottom chain off the bottom.