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dscottl 04-10-2002 04:34 PM

Mooring advice needed
I have recently purchased a 32'' full keel cruiser displacing six tons.

My anchorage is about 2 miles from the atlantic and is semi protected from surge.
I am mooring in 15 ft of water with a gravel bottom.

I have moored my 26 foot sloop here for the past 3 years. I used 1200 lb of steel and 40'' of chain. We dont use mushroom anchors here in fact I have never seen one used.

How much additional weight and or scope do you think would be good for the new boat. Also what size chain would you reccomend.


Pangaea 04-11-2002 03:52 PM

Mooring advice needed
Hi Scott,
Let me begin by saying this; gravel is a tough bottom for holding- one of the toughest. Let me ask a couple of questions. Whats the worst weather you saw on your mooring with your twenty-six footer? How did you fair? What do other people use? How did they fair in extreme conditions? How deep is the gravel?Or is it all gravel? Do you have access to a Helix mooring installer?


davealves 04-12-2002 05:49 AM

Mooring advice needed
When I moored my 36'' wooden ketch in Maine I used a 1 ton granite block, 1 X water depth of bottom chain (used Coast Guard mooring chain) and 2 X water depth of top chain(3/4 galvanized), all this went to a ball with 20'' of 3/4" nylon line (which was 1 x water depth) for a total of 4 to 1 scope. It held in 70 knots. All together it seemed like over kill but it always held no matter what the weather. The harbor was directly on the Atlantic coast.

Good Luck.

dave Alves
S/V Fluke

Pangaea 04-12-2002 12:38 PM

Mooring advice needed
Hi David,
The problem scott is facing is that his harbor has a gravel bottom. Gravel does not allow a suction to form so it''s easy to drag the weight or anchor accross the bottom. Iv''e seen this happen many times.In a bottom with deep gravel, you would need much more weight.


colehankins 04-14-2002 09:16 PM

Mooring advice needed
the QCYC use the following guide line for all the sail and power boats. Since the QCYC is the Philadelphias oldest YC i think they have come up(or copied) a good measure.

10lbs per 1 foot of boat, mushroom anchor

chain 5/16ths 2x the depth at high tide

3 swivels, one at the mushroom, one midway up and one on the float

1 good float I always used the taylor with the rod running right through it and a swivel on it

bridles,2x the height of the bow to the water

even with the gravel on the bottom the anchor will bite into it if the shank is the right size.
This configuration is not the panacea. you must PM your mooring and unwrap it every once in a while.
What did you use to pick up the 1200 lb weight at the end of the season??

Pangaea 04-15-2002 06:51 AM

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,


dscottl 04-16-2002 11:19 AM

Mooring advice needed

Seems like mainly gravel and hard pan sand. It is hard to get an anchor to grab. Any idea how much steal loses in weight when imersed. I''m thinking if I have enough Weight and scope it should be ok. I wish there was some general rule of thum I could use based on displacement. When I had someonwe dive on my old mooring it hadnt settled in any after three years. I had the primary weight 1200lb with 20'' of chain and another 200lb then from this I had another 20'' of chain going up to the Ball. I never had any problem, and I feel I had the right set-up but still am unsure how much more weight is needed. The old boat displaced about 1800lb compared to 11500lb with the new.

Good advice so far any additional would be helpful

dscottl 04-16-2002 11:22 AM

Mooring advice needed

No access to a Helix mooring and went through some pretty severe weather without any problems where boats in quieter bays did drag.

colehankins 04-16-2002 11:50 AM

Mooring advice needed
the mushroom anchors we use dig in to the bottom because the angle of the lip and the length of the shank. most of the moorings stayed in place and were hard to pick up at the end of the season. QCYC has 3 different bottom types, from a mud with clay to river sand and a hard packed clay. as the tide changes and the boats settle in the other side of the mushroom pulls the anchor in deeper. Its just advice. How do the other boaters hook down in the gravel??? Are there anyother boats there? Have you thought about getting a real slip?? you may also think about old railcar wheels stacked and welded together with a ring.good luck getting them back up at the end of the season

Pangaea 04-16-2002 04:11 PM

Mooring advice needed
I had a mooring in South Dartmouth, Ma. where the bottom was all sand. Hard sand. Did you ever hear about what happened there during Hurricane Bob? I can''t remember the exact number but dozens of moorings pulled out because people used mushrooms in hard sand. The boats were just lying there, on the shore, still tied to their land locked moorings. (And train wheels).This made me a believer about this hard sand thing. It made sence to me! Since then they cracked down. I spoke with the harbor master and the mooring tender, they gave me this info. The mooring tender (John) told me ,when I spoke with him about installing a mooring, the same thing I stress here. He had me go out and buy a 2,800 LB mooring weight (as I mentioned in my other post to you) with related gear. I went through a couple good blows there. It did the trick!
So.... my advice is to talk to mooring tenders... call or go to scrap yards and try to find a mooring weight. (I found mine in a scrap yard). It''s a once every 15 to 20 year thing but you''ll sleep well... take my word for it.
Tha besta luck.


P.S. Almost forgot; steel retains about ninety percent of it''s weight in salt water.
The foreign made mushroom is less.

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