Mushroom Anchor
Most commercial moorings are mushroom anchors with a length of heavy chain then a swivel then a lenght of lighter chain to the bouy. The chain is shakeled to the bottom of the bouy and the penants (rope that you put to the boat) comes off that same shakel. I set mooring as my spring job and pulled them in the fall to earn money for college. The length of the chains depends on the current, depth, wind conditions, wave conditions, and how crowded the mooring area is. A 250# mushroom can hold a 30 sail boat fine. Now your boat is probably smaller and lighter, so build your mushroom anchor. Try this, hit a couple of auto shops, or junck yards and get a 1)broken rear axel (from a rear wheel drive) 2)the worn out or broken drum that fits that axel, 3) The rusted bent or otherwise bad rim that fits that axel. Bolt them togeather and have a shop weld a loop on the end (inside end) of the axel. This is where you shakel (I prefer a swivel here too) your chain (the heavy one). Fill the drum and rim with concrete, (depending on the size wheel you got 13"-16.5") your anchor can weigh over 150#. Now for the heavy chain, get the biggest cheap chain you can find, try the shops again, and some of the places that buy scrap steel. The light chain should be 1/4-3/8 proof and new. It will rust out in time. Use a swivel to connect the two chains togeather. As for lenghts on the chains, well the longer the better. But this system with 2X depth of heavy chain and 1X depth of 1/4" hs held a 30' sail boat in 45K winds with no slippage on a sand bottom, and will hold even better in mud. I'm using a 16.5" set up I got all the parts for free and the welding done for a 6 pack of beer, I have 10' of 1" chain I got out of a junk yard (free) and 15' of 1/4" chain. I didn't have time to fill with concrete this year so it's not as heavy as I would like. It held my NewPort 23 with no problems and went through some 40K winds and 30K with 4' seas in Traverse Bay with no slippage. Total cost about $25. Oh I use 4' 3/8" pennants with an eye splied on each end (and a thimble at the shakel end) and a small foat (1/2 gallon milk bottle) to make catching the mooring easier. I'm moored in 10' of water, and it's too crowded to have a longer chain, but if you have the room it's better to have more heavy chain.