Paulk (I think) is talking about the Helix Mooring System which does not depend on weight to hold your boat; it is a different creature from the typical mushroom or dor-mor type anchors. Personally I have a 34'' sailboat. The harbormaster requires a 350lb mushroom type mooring. I have a 500lb dor-mor which buries itseld into the sea floor and gives alot more resistance that a typical 500lb mooring. Let it suffice to say that Paul is mistaken in his mooring weight estimate; a 200lb mooring will get dragged all over the place by the weight and windage of a 50'' boat. Check your local regulations and then go one or more sizes up on the mooring itself, the chain, and the penants.
West or Defender have guides within their catalogs but I would get the advice of a professional in your area. Also, if you are going for a mushroom type anchor, I would recommend that you spend a few more bucks and go for the dor-mor as it gives alot more holding power for its weight. (www.dormor.com) Good luck.