The thang...
Hi Tom,I put in a permanant mooring using an Anne's mushroom anchor like you're describing in front of my house on the Pamlico River in North Carolina. It too was in about 10 feet of water with a muddy/sandy bottom, with a long fetch.I had great results - mine never budged an inch - even in relatively high winds (50-75 MPH). I never rode out a hurricane on one, but I would expect similar results. IMHO, it's probably one of the better places to be in a hurricane, especially if it's located in a sheltered cove or protected area.Here's what I would suggest:1. Get a copy of Chapman's Piloting - there is a very clear and concise explanation about the construction of permanant moorings.2. I used an anchor larger than was suggested in Chapman's for an extra measure of safety. I think within the bounds of good reason, bigger is better.3. It's not a "set it and forget it" kinda thing. You should frequently check the integrity of everything once it's in the water. Constant wave action is HARD on mechanical components.4. During your frequent checks, you'll notice that the chain is getting shorter because changes in wind direction are wrapping it around the anchor on the bottom. You should unwrap the chain for maximum scope and so the chain is not bound.5. Buy high quality components. You're trusting your boat to this thing. It will, at times be the only thing that keeps your boat safe. Don't skimp.6. Keep a close eye on chafing of all components, not just mooring lines, but everything. You'll be surprised how much constant wave action can saw away at components.7. ALWAYS use at least 2 mooring pennants. If you run one to the port forward chock/cleat, and one to the starboard forward chock/cleat, it will reduce the amount of "porpoising" back and forth on the mooring.8. The only drawback I ever found was that my boat was always in motion on the mooring due to wave action, winds, rocking, etc. I thought this was a little hard on the boat, but it's just an opinion.I hope this helps. I'm no expert, but these are things I found out "by the seat of my pants."AdiosDebo CoxS/V El Coyote