Dragging my Rocna - Is my technique at fault?

[Celestialsailor]

I take the weight of the boat, divide it by the atmospheric pressure, add 202, then then consult my crystal ball. If I do that, my answer for anchoring is about as good as anybody else's...except, I'm right, like everyone else.

[BlackHeron]

Titusville can't be a difficult place to anchor because of all the derilict and flophouse boats. They've been there forever so if it was tricky they would have dragged aground long ago.

We've dropped the hook there a few times and once stayed in the morning field (too close to the ICW and wakes.). Never had an issue with setting the hook there other than it being an obstacle course to find a suitable spot.

[Lodesman]

Originally Posted by BlackHeron

Titusville can't be a difficult place to anchor because of all the derilict and flophouse boats. They've been there forever so if it was tricky they would have dragged aground long ago.

I guess that's one way to measure it. I only mentioned Titusville because I vividly remember the soft mud, and know it's close to Daytona. Curiously there were no other vessels around when we anchored - I noted it in our blog. We had decided to go there based on reviews in Activecapt, and decided to chalk it up to being outside of cruiser migration season and the weather was too crappy for locals to be out.

[BlackHeron]

You must be talking about a different Titusville. The one we pass in Florida has a dozen or more weirdo beat up boats (one looks like something out of Star Trek) just north of the mooring field that haven't moved in the last few years we have been cruising the ICW. They were all still there (seemed like there were more, actually) when we went through there going north a couple of months ago.

[waterman46]

5435yI stopped reading when I got to the part where you followed Rocnas instructions to do an initial set by snubbing the rode at only 2:1 scope with the boat moving. At that angle you are just going to drag it unless you are lucky. I always get a good set by letting out at least 5 or 6:1 before putting any stress on the rode. And then apply tension slowly and in stages, checking for drag each time. If not sure I let out even more scope and back down harder. Then when it holds I can shorten scope to suit.

[chasfgr]

Originally Posted by flightlead404

So I replaced the toy delta on my Hunter 38' with a 25kg Rocna original on 200' 5/16" G43. Should be sized correctly for my boat.

I've anchored out four or five nights and drug two of the five. Admittedly the dragging was in soft mud, but possibly my technique is also at fault.

FWIW I drug in the river by R42 (R44?) Veterans Memorial Bridge, Daytona, and at Sheepshead Cut just south of Fernandina. Both times in 15kts with 5:1 scope out. Sheepshead Cut I would never have anchored, very large fetch, wind opposing current, > 6' tidal range, right in the mouth of a creek, soft mud....ugly but was with another boat. I bailed after two attempts and picked up a mooring at Fernandina.

Successful anchoring in Lake Syliva, and by Merritt Island Causeway.

Onto my technique:
1. Bring boat to a stop at chosen point, aligned with other vessels at anchor nearby if any, otherwise into wind
2. Lower anchor until its resting on the bottom
3. If the wind/current is pushing the boat down wind/current then pay out the anchor chain to keep it just vertical until 2:1 (this from Rocna pamplet), otherwise engage in reverse idle to do the same thing
4. Snub the chain, look for the chain to be "bar straight" and not doing a "snatch and relax" or any vibration in the chain indicating skipping
5. Continuing the motion in step 3, go to 5:1
6. Back down on the anchor starting around 1,000 rpm, increasing to 1,600-1,800 rpm for a minute while checking bearings to nearby land-based points

Am I doing something wrong, or just unlucky with bottoms?

I think you are probably chancing your arm in a very soft mud bottom and the anchor is unable to get a grip on anything approaching solidity.
I'd suggest either:-
1. Using a <5kg chum about 2m from the anchor.
2. Trying tandem anchors, either on a Y chain or (less effective) one behind another.


I'm afraid riverine mud is notoriously hard to get a purxhase.


I'd. also leave about 20' before digging in the anchor in reverse.
I go up to max torque rpm (on my engine 1600rpm) until the boat fishtails. My anchor is a 15kg Mantus on a 9m boat weighing 5600kg in windspeeds up to 42kts constant, 62kts gusts.

[Lodesman]

Originally Posted by BlackHeron

You must be talking about a different Titusville. The one we pass in Florida has a dozen or more weirdo beat up boats (one looks like something out of Star Trek) just north of the mooring field that haven't moved in the last few years we have been cruising the ICW. They were all still there (seemed like there were more, actually) when we went through there going north a couple of months ago.

No same Titusville, but we anchored south of the Brewer bridge. I don't have access to my log-book so can't give an exact lat/lon but it was within a mile of the bridge iirc.

[JimmyDarci]

Hundreds of anchoring... not dragged once (knocking wood as I write this);
1. Buy BIG / BIGGER anchor. We use the largest Rocna we can comfortably install. 64lb for 46 foot catamaran. Basically a Hurricane rated anchor and then go up a size from there. If you would “never race with that thing on your boat”, it’s probably getting into the appropriate size range. Now add 50-200 feet of chain depending upon where you sail. On New England we use 60 feet of chain because not a lot of instructions on the bottom that require more than 60 feet. But the weight of the chain greatly helps both with the set and with the holding power of the set.
2. Hand set the anchor. Others are correct that hand set means you can “feel” the bite. It can be inconvenient compared to mechanically setting from the helm but you can both see and feel the set.
3. Do not set at 2:1 or 3:1 .... you can slowly set beginning at these variables
As you are expanding your scope BUT do not back down on it until you are minimum 5:1.
4. Unless you are stopping for a quick picnic on a calm day, let out minimum of 7:1 or more. If you cannot do so due to other boats or obstruction/land/depth issues, then rethink your anchoring site.
5. Back down with engine 1800rpm or so only after
Extending full scope. Wait for anchor to set a bit before you back down.

Setting an anchor is like rock climbing, you can have all the confidence in your gear but if the rock lets go, you will fall. Same with anchoring. Assume nature is going to play tricks on you and get either better gear. Then know how to use it with practice.

[R Hutcheson]

What you're doing sounds OK. I didn't look up the specs for your boat. Assuming it is sized correctly, the only thing that occurs to me is whether or not you are including the freeboard above the waterline in your 5:1 calculation. If you are, it may simply be the bottom. I don't know how high your engine revs, but you may consider trying the holding at a higher rpm to ensure a good set, making sure you build up gradually. I didn't hear you mention a bridle. It is possible that if you are in a reversing current situation, and you don't have a bridle, the anchor is being snatched out. Though frankly I would expect it to simply reset. I've been cruising almost two years on a 60' ketch with a 55kg Rocna. We haven't drug yet, and only had issues setting one time below a dam where all the sediment had been washed away and the anchor was riding on bedrock. After considerable slow backing down the anchor finally caught a ledge and we didn't move after that. Good Luck.

[Estica]

When anchoring I’m always moving backwards at least a little before slowly dropping tackle so as to be sure the chain doesn’t get fouled on the hook. And 5:1 at times won’t not be enough in challenging bottom or current situations. Even with the catenary effect of the chain. In the worst situations you can add a 50 pound kellet 10 or 20 feet (or more depending on depth) up from the hook. It keeps the angle way down and is a very useful addition.

[rslifkin]

Originally Posted by Estica

In the worst situations you can add a 50 pound kellet 10 or 20 feet (or more depending on depth) up from the hook. It keeps the angle way down and is a very useful addition.

No. Kellets are useless in most situations. The only time they serve a purpose (and it doesn't take 50 lbs) is to help a rope rode drop down straighter to avoid it fouling on the keel or other parts of the boat in light winds. In every other situation, adding the equivalent weight to the anchor will give a large increase in holding power, while the kellet will do basically nothing. In a good wind, even with a large kellet, you'll still pull the rode tight unless you're using a long length of heavy chain in deep water.

[s/v Jedi]

Reading these posts feels like having an appointment at the dentist

Seems most without a windlass do it right and most with a windlass do it wrong. Seems like the Jedi rules for anchoring are forgotten

Those without windlass: get one, you earned it

Those with windlass: learn how to use it! That “down button” is for adjustments, not for slowly lowering your anchor. The anchor must be dropped, using the clutch. You actually have to move yourselves to the foredeck for anchoring also, don’t send your wife forward, it’s your job.

Bring the boat into the wind towards the chosen spot. Kick the anchor over the roller or push “down” so that it hangs vertically below the roller, just touching the water. At the right spot and with the boat moving backwards, drop the anchor by loosening the clutch. If very deep, control speed. With the boat moving backwards, chain should run out freely and equal to distance moving back. Continue until at least 60’ of chain or 3:1 scope is out, then carefully tension clutch so that the chain stretches out but when it does it can still pull chain out. Continue to 5:1 scope if not there already, then fully tighten clutch.

If soft mud, wait at least an hour before setting the anchor. If wind is up 15kts+ you’re done. If sand/clay bottom or no wind, pull with engine in reverse, looking at objects to the side to detect movement.

Don’t forget rule #1 use only one anchor for 99% of cases. Buy a bigger better anchor if one doesn’t hold you.

[lvictorlucas]

I hate to add one more opinion but the manufacturers guidelines are only that and are designed to sell anchors. They are useful for overnight in calm conditions over a good holding bottom without a strong or reversing tide and use of an appropriate rode. The major factors being the appropriate type of anchor for the bottom, max gust (not average or RMS), rode scope (including height of bow), rode stretch (and shock or jerk as with chain) and anticipated change in direction of tide and wind. Most of my anchoring failures have been due to reversing of current ot wind direction.

[rslifkin]

Originally Posted by s/v Jedi

Those with windlass: learn how to use it! That “down button” is for adjustments, not for slowly lowering your anchor. The anchor must be dropped, using the clutch. You actually have to move yourselves to the foredeck for anchoring also, don’t send your wife forward, it’s your job.

Bring the boat into the wind towards the chosen spot. Kick the anchor over the roller or push “down” so that it hangs vertically below the roller, just touching the water. At the right spot and with the boat moving backwards, drop the anchor by loosening the clutch. If very deep, control speed. With the boat moving backwards, chain should run out freely and equal to distance moving back. Continue until at least 60’ of chain or 3:1 scope is out, then carefully tension clutch so that the chain stretches out but when it does it can still pull chain out. Continue to 5:1 scope if not there already, then fully tighten clutch.

I'm curious what the issue is with power dropping the anchor? I could see a problem with a very slow windlass on a windy day, but mine will drop somewhere around 100 feet / minute while powering down, especially while it's got the weight of the anchor and chain pulling on it before the anchor hits the bottom. With the boat moving slowly or being blown by the wind, I've never had a situation where the rode has gone tight due to the windlass dropping too slowly.



Generally I signal back to the helm to adjust boat movement as needed if it's either too fast or too slow relative to the speed of the rode paying out. I drop and raise the anchor standing on the bow with the remote and give hand signals to the helm for boat movement.

[JimmyDarci]

[QUOTE=rslifkin;3421745]I'm curious what the issue is with power dropping the anchor? (End quote)

IMHO.- power windlass drop is great - when it sets correctly. My issue AGAINST using the power to drop the anchor and set it is that when you manually keep a hand or two on the line while paying out scope, you can literally feel when it drags or something goes awry. For that reason, I do use power windlass to raise and sometime even to pay out a bit more scope but not to lower. If too heavy, You could always use the power to set the anchor on the bottom and then pay out the line by hand. “Jedi” powers they are not, but this is akin to a sight impaired person maximizing the other senses while in the dark. A poorly setting anchor will send small tremors or even a larger jerking sensation back up the rode/chain.