Tonyjo, when you refer to mast pumping, do you mean the mast is visually/ physically moving while at anchor or docked? If so, you need to check how your mast is chocked above and below and if that is correct, you definitely have undertuned your rigging or have a broken attachment. The danger to this is that you potentially may damage the structural intergrity of your boat by the overwhelming and unnatural stresses you are creating. If you are slogging into large head seas, some pumping is inevitable, but not at anchor or the dock. You need to consult a professional rigger or a knowledgeable sailor at your home dock. In any event, I wouldn't wait too long. Best, Ron