Oversized Anchor for Long Term Anchoring

[judgesmail]

Hey y'all!

I have a 1984 28' Oday. I currently have her in a slip in New Bern, NC but I'm considering moving her to Town Creek in Beaufort, NC and keeping her anchored in the basin there. Anchored sailboats in the basin have been seen, more than a few times, pushed ashore into the rocks after a stiff breeze.

Isabelle displaces about, call it 8000lbs. Bottom in the basin is more sand and less mud. I have a bruce style 16.5lb anchor currently and a danforth secondary.

Welcome any advice some of you salts can offer in terms of how much anchor/chain rode I should get to safely keep Isabelle in the basin full time (while I'm not sailing her, of course).

I would really rather not drop two anchors, either in line, Bahamian, or otherwise - I'd rather drop a big hook once. I don't have a windless.

Thanks very much in advance!


"It's easy to grin, when your ship comes in, and you have the stock market beat."

[roverhi]

I'm not a fan of the grossly oversized anchor that some seem to subscribe to. Even if you have an powered windlass there will come a time that you'll have to retrieve it by hand. Heavier anchor and chain makes for a back challenging evolution.

Having said that, think you are a bit light on the Bruce. Would go with a 20 plus pound Mantus Supreme or similar hook. My rule of thumb is an anchor weight twice the boats displacement to the left of the comma plus a bit. Otherwise, your boat displaces 8,000# so 8 times 2 equals 16# plus. That puts you right on the line without the 'plus' so would go up a size.

Most boats go up on the rocks because of a failure of the anchor rode, not the anchor. If you use a rope road be very careful to provide proper chafing gear and preferably an additional pendant attached to the rode with a strap. You can buy Exotic prespliced straps to do this. Good idea to have one of those in any case to free up a winch overide without having to cut the line.

[judgesmail]

Thank you, sir! I really appreciate you taking the time to provide those comments; they're v. helpful to me. I'll take em on board.

All the best,

JT

[UNCIVILIZED]

I'd say an oversized Mantus as well. Say 25kg which is twice what they recommend as a storm anchor for a boat of that weight. For $450 + shipping, so under $500. Mantus Anchors, 8 to 125 lb Sizes Available
And the mega overkill in terms of weight is because permanent moorings tend to be designed a lot heavier duty than are summer moorings, or even storm anchor systems. So while this isn't a "permanent" mooring persay, you want it to stay put.
https://www.mantusanchors.com/mantus...anchor-sizing/

How much chain is going to depend on the water depth, & must also factor in for tide, rain swollen rivers, & bow height. And while 1/4" G40/43 would probably be fine, it would restrict you on shackle size a lot. So 5/16" G40/43, along with Crosby high load shackles.
https://www.mantusanchors.com/mantus...e/rode-sizing/
Marine Anchor / Bow Shackles - Load Rated

Coupled to an oversized, purpose built mooring pendant. Like Yale's Polydyne or similar, with lots of extra chafe sleeve. Such as Spectra anti-chafe sleeving, for most of the length of the pendant. Or at least anywhere it can conceivably touch the boat, or the chain.
Defender.com Search Results: mooring pendants

There are other styles of Crosby high load shackles that work as well as the above linked ones, if not better. Which, they're easy to find. And you'll want to have a few different sizes on hand when you're putting things together, as rarely does everything fit as perfectly as it does on paper.
Also be sure to wrench tighten the shackles closed, & then mouse them using both wire (Monel, or Stainless), along with 1.5-2mm Spectra cord.


Note that when you're done with this "mooring", some of it's parts can be sold if you desire. The anchor for example, without taking too much of a hit in the wallet. Probably several of the other bits too, if you so desire.

[judgesmail]

Thanks, Uncivilized!

Now I'm looking at the Dor-Mor 450lb pyramid and a full mooring system and just keeping my current anchor set-up. I'm mostly a day sailor or I cruise the inner banks on long weekends and maybe go outside down to South Carolina or Georgia once or twice a year. For 2k, I could hook up pretty safely and I don't plan to leave the area or upgrade the boat anytime soon, so it seems like a decent option, as I won't be paying any slip fees so I'll make up the cost in a matter of months.

Any thoughts on that idea? We obviously get hurricanes in Beaufort so I should be good up to 67kt sustained with the 450lb rig.

Anyone have experience putting in a Dor-Mor system - experiences to share with this?

Thanks, y'all.

[LoudMusic]

Originally Posted by judgesmail

Thanks, Uncivilized!

Now I'm looking at the Dor-Mor 450lb pyramid and a full mooring system and just keeping my current anchor set-up. I'm mostly a day sailor or I cruise the inner banks on long weekends and maybe go outside down to South Carolina or Georgia once or twice a year. For 2k, I could hook up pretty safely and I don't plan to leave the area or upgrade the boat anytime soon, so it seems like a decent option, as I won't be paying any slip fees so I'll make up the cost in a matter of months.

Any thoughts on that idea? We obviously get hurricanes in Beaufort so I should be good up to 67kt sustained with the 450lb rig.

Anyone have experience putting in a Dor-Mor system - experiences to share with this?

Thanks, y'all.

Before I got to this comment I was wondering if there were options for short-term mooring balls, and if that was even legal.

[UNCIVILIZED]

I'd be 100% guessing on building a hurricane proof permanent mooring. And were I looking into such, I'd do a lot of research in the usual areas, along with asking Thinwater for any suggested reference sites or pub's. Since he's connected with folks with some expertise in those kinds of data bases (I think).
But Practical Sailor, & Professional Boatbuilder definitely have this kind of info on hand, if not in published articles in their magazines.

There's also the option of buying or making a couple of huge mooring anchors, or moorings, & attaching them together, & then to your boat via a link plate setup like this. Hurricane Mooring System — Colligo Marine®
They're easy enough to make, have made, or cobble together from off the shelf parts. Though if you make'em, use quality plate stock, NOT scrap metal. Dye penetrant test it. And have everything properly hot dip galvanized.

I say not to use scrap metal, as you never know what you're getting. It could be a crap alloy, be rife with unseen micro fissures, have led a brutal life previously, etc., etc.

For example some guys will make knives or swrods out of old truck leaf springs. Which is good steel for that, metallurgically speaking. But due to the life it's led, it has all kinds of micro fissures. And often enough, they'd show up, before or after heat treatment, via dye penetrant. But few guys think to check. However when they're testing their finished knives, sometimes they break under relatively low loads due to said unseen cracks. Thus destroying dozens of hours of labor, & plenty of $ in materials, consumables, & metal treatments.

[barnakiel]

Our boat is similar size to yours. We are using 35 pounds of anchor and 100 pounds of chain. We stepped up from a 22 pounder (which was big enough anyways).

If you opt for an even bigger anchor, look at the newer styles: Fortress, Spade, Beugel, Manson, Rocna - in more than one way you can at times get a lighter anchor with better holding. You will likely do with a 22 pounder then.

I find a 33 pounder the max I am going to lift from 30' of water. No anchor winch here.

Cheers,
b.

[masonc]

I have a 33ft boat, I just bought a used old 65lb Danforth, added 10ft 1/2" chain, and 1" rope to beef up a mooring we use in one location. When I leave, I leave it there. It cost $100 and I sleep at night. Buy a huge anchor and leave it down.

[Snowpetrel]

I use a rule of thumb of LOAxLOA (ft)/anchor wt (lbs) should be somewhere between 20-30 for a serious sized anchor on a normally proportioned vessel. With lower numbers being better.

So for an anchor ratio of 25 you get a 31lb anchor. For the super heavy end of the scale (20) go a 40lb or lighter end a 26lb (anchor ratio of 30). Practically speaking any next gen anchor around the 25-35 lb mark should be about right.

IMHO Your current anchor is almost certainly far too small for strong winds or poor holding grounds, both due to its size being to small (28*28/16.5=47.5, wsy too high) and its type. Bruces tend to have less ultimate holding capacity for their weight than most other anchor types so its better to err towards an anchor ratio of 20 rather than 30 with these anchors.

[Elie]

If you plan it to be a sort of quazii permanent mooring you have to take into account the consequence of wind shifts and the ability of the anchor to reset quikly after a big wind or tide change of direction. Some very good anchors can't reset(Danforth?) after being pulled out.
And keep in mind that old Britany fishermen saying: 'Too strong never fail'. So the bigger the better...

[DMCantor]

We've always subscribed to the theory that your anchor is about the right size if your neighbors in the marina are laughing at you. We have a Rocna, one size larger than their (conservative) recommendation, and it has never let us down.

[fatherchronica]

I am a fan of a big anchor. We have a windlass though. My 36' boat displaces 23,000 lbs, plus 200 gallons of diesel and 180 of water, plus all of our crap, which is considerable. The charts I read recommended about a 33 to 35 lb anchor, but we were right at the top of every chart, so we went up two sizes to a 55 lb Rocna with 50 fathoms of 5/16" rode. We have been in some precarious situations watching yachts of all sizes drag past us, and we have never moved enough from dragging to set off our anchor alarm. Swinging to the wind has set it off, but in the mornings we were always where we started. We were in Balandra once when a Corumel came up blowing directly into the bay. We had come in right at sunset and it was mostly full of big power boats, so we went inside into about 9 foot at low tide, about 100 yards off of the beach. At 2 a.m. we woke to 40 kt winds. We let out a bunch more scope, reset the anchor alarm and we were right there next morning. During the night we had 2 and 3 foot waves breaking before us and under us. Several boats dragged and either reset, left in the night or motored in gusts to relieve the strain. I am in my mid sixties and survived a life as a framing contractor with three back surgeries and two shoulder surgeries and a ton of arthritis, so I have no option to not have a windlass and continue sailing. But when I was younger, into my late forties I routinely contributed to my wracked skeleton by weighing 35 lb anchors by hand although until we started to cruise we never had all chain rode. What is really hard is round hauling 50 fathoms of drift net with a few thousand lbs of salmon 15 minutes before the opening ends.

[zeehag]

i use a slightly oversized bruce with 194 ft chain. i keep 120-160 ft on bottom. no rope rode. chafe happens in long term anchoring situations.
chafe is not your friend

[KP44]

Everyone has an opinion on anchors.
If you look at the overall picture, anchor weight is only a small part of the system. If I have out 200' of chain, that's about 200 lbs. The difference between a 44 pound Bruce (rated for my boat) and a 66 pound Bruce (oversized and far more holding power) is a mere 22 pounds. So my windlass is hauling up 266 pounds instead of 244 pounds.
Always oversize your ground tackle and sleep better.

Another opinion. Never use a "lunch hook". Never bother with a small anchor when you anchor in a cove for lunch. There will be a time when you go ashore "for 15 minutes", and you will spend the next 6 hours worrying about your boat. That's why you bought a windlass and a good, big anchor. Always use your main anchor.