Mooring advice needed
Hi again. Look... let me begin by saying this... if you drop a little 300 lb mushroom in gravel, you will be sorry. It is impossible to create a suction in gravel. You have to have a suction or enough weight or the mooring will just slide across the bottom. This is not my oppinion-this is fact. If your in a harbor where the laws of physics cease to apply, you''d better stay there.
It is quite probbable that the gravel is only so deep. If it is only say, three or four feet deep, then you can drop your mooring and wait a couple of weeks (with no load on the mooring so it will settle straight down) then tie-up. But now there''s another question. Whats below the gravel? You should not use a mushroom in hard sand, it wont penatrate the bottom. You have to know whats there, thats very important. If it''s hard sand then you should use a mooring weight. These are a solid piece of cast steel, shaped into a half of a sphere, with a concave bottom. these are better in sand than mushrooms but are much heavier. If you have sand below, use the weight (2 to 3,000 lbs). If you have mud below, use the mushroom (no less than 500lbs no less than 3/4'' bottom chain- no less than 1/2'' top chain). If it''s all gravel, go with the biggest hunk of cement you can get out there. Remember, cement looses up to about 40% of it''s weight in water. I don''t think swivels are really nesessary because when you drop the mooring to go sailing, it will twist back if thereis any twist at all. If you are going to use them , use one, thats all you''ll need and remember their your weakest link. Go way oversize. You can get them from a comercial fishing retailer.(Check-out my post in General Discussion-mooring vs dock ,if you want) Scrap metal yards sometimes have mooring weights and they will have other very heavy items. They will deliver.
As for a float? Don''t use the ones with a metal rod going through it. It doesn''t take long for them to rot away. Get an inflatable ball that allows the top chain to pass through the center and keep the chain from pulling back through by placing a large shackle at the end of the top chain. Also remember, the less connections, the better.
hope I helped,