Anchor Chain

[RobRocket]

I seem to be having trouble holding the bottom. Is there a theory on how long my anchor chain should be or any other thoughts why I might to be having troubles.
My boat is only 4.5m almn

[drevil]

You will need at least a couple of metres of decent chain if it's a sand anchor, as the chain needs to be lying flat on the ocean floor so that it bites in.

It's not so critical if it's on a reef anchor.

[RobRocket]

Sorry for the lack of detail. It is infact when trying to hold on reef.

[Kerry]

Geez, in between typing a response and hitting the post some b..... :-X decides to move it and then says the post is locked and of course looses the whole reply #[smiley=thumbsdown.gif]

Now even forgot what I said?

Chain on a reef pick, kellick doesn't go astray but doesn't need to be as long or heavy as one might put on a sand type anchor.

Depending on the bottom type, conditions etc and reasons why it's actually not holding maybe a heavier anchor or longer prongs and/or heavier prongs if it's a bending problem or maybe more rope. A mooloolaba pick even but with a reasonable reef pick and enough rope a 4.5m tinnie shouldn't take a lot of holding.

Cheers, Kerry.

[peterbo3]

Rob,
How deep is the water & how much rope are you paying out? As Kerry says, chain is not that important on a reef pick for holding purposes. More to prevent your rope being chafed or cut by the reef.

[sharkbait]

Hey Robrocket, I'm in a 4.2 mtr tinny but very high sides, pretty heavy for its length. I don't use chain for my sand or reef anchors under 30ft depth, In very heavy current this may not apply but for the most part I've found they are too noisy and completely unneccessary.
We always stop close to our intended spot and check the drift, allowing for plenty of extra rope to compensate for no chain. Both anchors are rated for a 5 mtr boat, maybe the one you have is too small? someone is going to tell me I should always use chain but I'm not convinced, mine always hold bottom pretty much straight away. I also have an anchor retrieval buoy which helps get it off the bottom. What type of anchor are you using on the reef and what depth are you trying to anchor in?

[neptune]

I think by law you have to have at least 18m of rope for a vessel of your size. They say to lay out 3 times the depth of the water you are in with your anchor rope. I have the same sized tinnie with very high sides and have never had any problems,but I do have 3 meters of chain and it is tested chain which has shorter links. the shorter links gives you more weight over a given length than standard chain.

[RobRocket]

I begining to believe that my anchor might be too small. Im going to make up a larger anchor and see if this is it.
If spoke to spearos who leave their boat anchored whilst diving and they all say that you need at least your boat length in chain.

[peterbo3]

Rocket,
Too much chain on a reef can see the chain hooked up on a bommie or jammed in between rocks. This negates the design of the bendable prongs 'cos chain doesn't bend or break. Divers who leave their boat really have a vested interest in having it still there when they surface & they are able to get down & release their anchor if it
hooks up. Try the bigger reef pick & make sure your prongs are not opened out too far.

[Kerry]

On a reef pick 2m (6 feet) of chain is generally enough. It's probably more dependent on the bottom type as to what size/type pick you use.

For conditions around here I basically use a fairly standard reef pick (with 6 feet chain) but cut the prongs short and bent sharper, which makes it a little harder to bend straight.

It's going to depend on the bottom to determine the best setup.

Cheers, Kerry.

[locomotion]

Rob
i have a 5 mtr fibreglass which has probably 2 mtrs of chain between the anchor and rope so yeh 4.5 mtrs of chain is far to much

cheers andy