anchoring in coral

[seandepagnier]

I think it's possible to use rock climbing type anchors to anchor in coral and other difficult areas. Basically carefully put slings or cables around coral heads or other obstructions. It is also possible to drill and install bolts into large rocks if you have and underwater drill capable. From there, you simply run a line and attach floats to the line to keep it off the bottom and to provide shock loading.

Additionally, when anchoring in sand or mud, you could simply fill a sea-anchor with whatever is on the bottom using a pump.

Using these two methods completely avoids the need to use chain or metal anchors which saves a lot of weight and avoiding using metal means there is no corrosion on ground tackle.

[TeddyDiver]

WTF? You don't anchor in coral period.. If local authorities find it necessary in some places they install permanent buoys.

[boatman61]

'Boats' a Law unto his own Logic... as long as the F&F are not disturbed alls good..
Though using Live Coral heads would be disappointing..

[atoll]

Originally Posted by TeddyDiver

WTF? You don't anchor in coral period.. If local authorities find it necessary in some places they install permanent buoys.

in many lagoons anchoring in or near coral is un- avoidable.
in much of the 2nd and 3rd world the local authoraties spend there budget trying to stop the locals dynamiting the reef,so little money left over to lay moorings for transient yachts.

I carry a 12mm stainless cable,just for this purpose of creating a tempory mooring using a coral head.

[TeddyDiver]

Bad excuses IMHO, as a diver I have seen the damage done and can't promote such behaviour.

[Claude_Marie]

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[atoll]

Originally Posted by TeddyDiver

Bad excuses IMHO, as a diver I have seen the damage done and can't promote such behaviour.

coral bleaching,lion fish and crown of thorns starfish probably do way more damage than anchoring in coral.

but you definitely have a point,and I generally will do my best not to anchor in coral,purely because it is very hard on your ground tackle.

[Wrong]

At Chagos Archipelligo in 2002 a couple of sailors went arount the atoll collecting fishermen's net buoys that had broken free and eventually landed on the shoreline (along with the flip-flops).

The buoys were distributed to other sailors who then attached the buoys to the chain in order to lift it above the coral, thereby preventing it from dragging accross and damaging the coral. Anchors were set in sandy spots.

Worked.

[seandepagnier]

Originally Posted by atoll

I carry a 12mm stainless cable,just for this purpose of creating a tempory mooring using a coral head.

How does it work for you? Do you use nylon to the cable and floats on the nylon?

Originally Posted by TeddyDiver

Bad excuses IMHO, as a diver I have seen the damage done and can't promote such behaviour.

I am proposing a method which avoid damaging the coral, provides better holding, and reduces ground tackle wear and weight.

Compared to coral bleaching, anchors have negligible effect.

All of the dive boats I have ever seen go and enjoy the reefs when their boats and compressors are powered from fossil fuels which are causing coral bleaching! The priority should be to make this illegal first, along with all forms of engines.

If there is ever a time when anchors are a significant source of reef destruction, then we should make that not allowed, but for practical reasons I am proposing not to use conventional anchors on reefs anyway.

[atoll]

Quote:


Originally Posted by atoll View Post

I carry a 12mm stainless cable,just for this purpose of creating a tempory mooring using a coral head.

How does it work for you? Do you use nylon to the cable and floats on the nylon?


generally chain or another bit of cable,only used it a few times,used it in chagos and the lagoon in Mayotte where anchoring can be difficult due to depth(40m) or bommies very close together( chagos),and not enough room to swing

[boatman61]

Anchors its true are a small part of the equation.. a few feet digging in.. however the chain causes a large amount as it scours back and forth across the bottom.. bouying up the chain is a bad idea as your weakening the effectiveness of your ground tackle by shifting the pull to your 1st bouy.. potentially causing even more damage with your boat battering itself to bits on part of the reef/corals when you drag..

[Wrong]

Originally Posted by boatman61

Anchors its true are a small part of the equation.. a few feet digging in.. however the chain causes a large amount as it scours back and forth across the bottom.. bouying up the chain is a bad idea as your weakening the effectiveness of your ground tackle by shifting the pull to your 1st bouy.. potentially causing even more damage with your boat battering itself to bits on part of the reef/corals when you drag..

Bouying chain, like any other possible method of securing your boat in place, depends on circumstances.

In Chagos, Boddam anchorage is very well protected from prevailing wind during the cyclone season and has a very low probability of being affected by one. There are occasional squalls, but again, protection is good. So, lifting the chain does not present much of a hazard for dragging due to reduced scope at the first buoy.

During the transitionary period when wind direction can shift putting you on a lee shore, moving to the east anchorage where there are more sandy areas free of coral is usually the norm. But, in 2002 due to frequently shifting wind I opted to leave earlier than most consider safe. Fortunate for me, because shortly thereafter a ferocious wind blew in from the N.W. directly through the entrance. A ferro cement ketch in the east side anchorage dragged onto coral and sank very quickly. Fiberglass boats also dragged onto coral but none sank.

[Emerald Sea]

There is a coral anchoring method described in this blog

http://www.sailingtotem.com/2011/03/...ling-with.html

Ultimately, try to avoid coral and find a bit of sand. We are in the Maldives presently with coral all around and we manage to find a sandy spot to launch the hook followed by a few fenders on the catenary over bommies. I expect the same will be found in Chagos in a few weeks.

Despite what the above comments say, mid water buoys (fenders in our case) do not affect the holding power of your anchor providing you have adequate scope ie min 1:4, 1:5 or more is better. Simply, as your vessel moves aft with increased wind, the buoyant fenders with elevated chain will further submerge as the chain comes under strain. I would suggest however that you attach your fenders on the chain after you have power set.

Steve


Steve
L450
SV Emerald Sea

[barnakiel]

NOT anchoring in coral is only possible when sailing in non coral waters.

I think it is wise and thoughtful (for coral, and for your rode) to avoid anchoring in coral. And I know we all do. For who likes to wake up in the morning and find their rode neatly wrapped around a coral head?

Most often, there is enough space in between the coral to drop the hook and then often a second anchor may stop you from swinging the wrong way.

Slings? Rock anchors? Perhaps. But send me someone who will place the slings and loops around the rocks, and who will retrieve the gear next morning.

b.