How do I set up a mooring

[jimhen]

I've been around boats for ever but always hauled them to the landing. I just got an opportunity to moor. This is on a lake abt 10 mile in length and faily protected. in about 5 - 8 feet of water.I was thinking of sinking a 5 gal can of concrete, shackeled to a chain to the bouye. Is this under/ overkill ? and do I need scope? how much ?

any sugestions would greatly be appreciated.

 

[Reel Poor]

Re: How do I set up a mooring

Did you look thru the similar threads at the bottom of this page? There is a lot of good information there.

 

[tashasdaddy]

Re: How do I set up a mooring

what are you mooring a 12' tinny or a 30' cruiser.

 

[steveziv]

Re: How do I set up a mooring

any sugestions would greatly be appreciated.

I suggest you go to amazon.com and buy a recent copy of Chapman's Piloting & Seamanship, the most comprehensive guide to, well, piloting and seamanship! It tough to stump Champmans.

(Sorry for the non-answer)

 

[jimhen]

Re: How do I set up a mooring

I have a 16.5 runnabout with a merc 120 I/O. not sure abt it's weight. The lake here is stable without much variation in water level. There is no significant current although it goes under a bridge and becomes a river about 1/4 mile from my site.Most docks are on pilings rather than floating. From the other threads I've read it seems that most are talking larger boats subject to more sever weather. I guess I am left wondering if the 5 gallons of concrete... maybe 75 # is enough.

 

[tommays]

Re: How do I set up a mooring

If you google for mushroom moorings you should find some idea about the weight you need to hold the boat

A 5 gallon pail is not gonna cut it


Tommays

 

[alden135]

Re: How do I set up a mooring

I guess I am left wondering if the 5 gallons of concrete... maybe 75 # is enough.

It won't weigh that in the water.

 

[Coors]

Re: How do I set up a mooring

Concrete has bouyantcy? I think that bucket would drag across the bottom.

 

[jimhen]

Re: How do I set up a mooring

never thought that concrete would be bouyant, but I suppose it is. I did a look up on google and found that 5 gallons by volumn weighs 98#.... and it did mention the bouyancy as well.

My site is well protected, shallow and on the south end of the lake... storms all come out of the south. Someone had mentioned using 250# on a 24 foot boat... 10# per foot. I am thinking to drop two buckets chained together. Not being in a coastal situation I am reluctant to drop hundreds into mooring gear.... but I don't want to be a knukle head either. If I am just being stupid I hope someone will say so. I think my skin is thick enough to take it.

 

[BillP]

Re: How do I set up a mooring

Two or three anchors spaced out at 180 degrees or equally in a circle, joined in the middle with one line up to the boat is all you need. Bottom type will decide what type anchor to use. For sand you could use 8 lb Danforths on a 16'r and it would hold in any weather. I've used moorings for yrs at a time made this way and gone though tropical storms with them. Smallest was 28' on (2)13lb Danforths and largest was (2) 22lb Danforths on a 42'r. The 42'r was moored on a 500lb concrete mooring once and it bounced a mile down the river the first time 25kts hit. Concrete's specific gravity is a lots less underwater...I learned later.

bp

 

[Tredeb]

Re: How do I set up a mooring

Everything is buoyant.

It is a simple calculation:

Metric: freshwater weighs 1kg for 1 litre of space displaced
Imperial: Water weighs about 8.3 lbs per USgal.

The amount of water displaced will be the buoyant force. Just subtract it from your overall weight and you will have the effective weight.

typical concrete is 2400kg/m3 which works out to 45 kg or 100 lb
subtract 18.9 kg or 41.6 lb for buoyancy
leaves you with around 58 lb effective weight

 

[alden135]

Re: How do I set up a mooring

You can buy a good, purpose built, mushroom mooring for around $1 per pound.

 

[jimhen]

Re: How do I set up a mooring

yep, I think I am getting it. The more I research this the iron seems the only way to go. I am just a ways off the coast so finding a local resource is unlikely and the freight on 150# seems $$$. I may get a local to fabricate something for me though.

 

[Scout Sport Fish]

Re: How do I set up a mooring

Well acually concrete can become neturally boyant over time I believe becasue water seeps in between the grains.

 

[Tredeb]

Re: How do I set up a mooring

Well acually concrete can become neturally boyant over time I believe becasue water seeps in between the grains.

That would probably make it heavier as the space would either be occupied by concrete, water, or air. Any water space would not contribute to buoyancy, air space would add to buoyancy, and concrete would be against buoyancy.
I agree that the buoyancy may be reduced over time if the air is replaced by water.

 

[jimhen]

Re: How do I set up a mooring

http://www.inamarmarine.com/pdf/Moorings.pdf

this site has some great stuff about all considerations. btw there are some problems with mushrooms in certain situations.... good reading. ( Living on the coast must be nice but trying to hold down a boat in a hurricane must be a pain ! )

 

[BillP]

Re: How do I set up a mooring

Surf around on this site. It's the best and most accurate you will find about anchoring and the tackle to do it.

http://alain.fraysse.free.fr/sail/rode/rode_b.htm

 

[RubberFrog]

Re: How do I set up a mooring

How much is an old block from the junkyard?