Anchoring

bobh

bobh

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I seem to always have difficulty getting my anchor to set. I have a 25' boat and I'm using a 12 lb Danforth with about 4' of chain. I have about 250' of rode.

Yesterday I was at the Red Bull Flugtag event in Philly. There must have been 200 boats anchored in the river...right around where the duck boat went under. I just couldn't get my anchor to set - and I tried a few different areas.

Conditions were difficult - very windy, water was about 55 feet deep, and a strong current - but there were 200 boats of all sizes that were successful! I was also single handling.

If it was a one-time thing I would chalk it up to the conditions, but I frequently need several tries to get the anchor set.

I'm not a novice but this is one area that continues to frustrate me. I always check the other boats to see what's happening. Yesterday I dropped in the direction that all of the other boats were pointing, I made sure to drop way ahead of where I wanted to end up - as the anchor dropped it was drifting under the boat (strong current)- I would back down but could never get it set.

Anyway - what tips do you use to get the anchor set - most of the time I am single handling.
 
I would start by adding more chain, I use about 12 feet, then asking around to see what brand and type of anchor other boaters in your area have had luck with. Different bottoms require different anchors.
Good luck!
 
I agree with adding a bit more chain.

But, with proper scope the Danforth should set quickly and securely. I also use a Danforth and have never ever had a setting problem.

If your current and wind were substantial you may have needed at least all 250' of your rode and more in 55' of water. If you put out less than that may have been your problem.

If both wind and current were strong you should have had closer to 7 to 1 scope.

Bob
 
As stated you need more chain. But more important is scope. For 55' of water you do not have enough rode. Scope is 5-1 on a calm day, 7-1 when it is windy and up to 10-1 or more for a storm. Remember depth is measured from the top of the bow, added to water depth, which can make a big difference.
 
i dont' recall off hand, but a 12 lbs seems a bit small for a 25 footer... always go at least one size above what you find in selection charts. 4' of chain isn't enough as others have mentinoed.

in 55' of water, you'd need all 250' of rode and still that may be short depending on wind and current.

one issue with a danforth is that once they drag and pick up mud and grass you end up with a mud ball that will not set. If you drop anchor in a current/wind or back down too fast, before enough rode is paid out, you will also drag it and clog it.

I have a Fortress (danforth style) on my boat and if wind/current is strong i usually slow down the drift with the engines to give a chance to the rode to be out before the anchor starts getting pulled on the bottom.

In addition to undersize anchor and not enough chain, the most common mistakes are not enough scope and backing down too fast on the anchor before it sets.

anchoring is the most easy thing to do, and the most easy to screw up!
 
"water was about 55 feet deep"

55 ft, plus 3 ft ( guess ) from water to bow = 58 ft.

58 ft x 7 ( recommended scope ) = 406 ft.

250 ft of rode, divided by 58 ft = scope of 4.3

---

If you had used the entire anchor rode, you would have had a scope of 4.3, which is less than the desirable minimum of 5. In a strong current, you would have wanted a scope of 7:1, or about 400 ft of rode.

Basically, you did not have enough rode out.

For best results, you want a scope of between 5:1 and 7:1, using the greater length as conditions become worse, and the shorter scope when conditions are close to ideal.

Always include the distance from the water surface to the top of the bow in your calculations, which is why I added 3 feet to your stated depth of 55 ft.

( water depth, surface to bottom, plus bow height from surface ) times 7 = rode length.
 
quote:
Originally posted by bobh

Yesterday I dropped in the direction that all of the other boats were pointing, I made sure to drop way ahead of where I wanted to end up - as the anchor dropped it was drifting under the boat (strong current)- I would back down but could never get it set.
Click to expand...


I agree with some of the others, you don't have a heavy enough anchor and you have far too little chain. Also, it's going to be very difficult to anchor in water that deep and a strong current.

My guess is that you should go up at least one size in anchor and use 24' or more of at least 1/4" chain. You might find that a plow or claw anchor sets easier, it depends. Find out what other boaters in your area are using.

The book "Chapman Piloting" has a lot of good information on anchors and anchoring. Pick up a copy if you don't already have it and study it.
 
I don't think the scope is the issue. Sure it would be nice to have 7:1. I routinely anchor at 4:1 with no problem; only because of boat congestion. While everyone will say add more chain, that is probably the best thing to do. In my opinion, 10-20% of the rode chould be chain. If you have to lay out 250' of rode, you should have at leat 25' to 50' of chain. Also keep in mind the type of danforth style anchor you have. Some are better than others. Fortress anchors seem to dig in really good as well as Danforth Hi Tensile anchors. Some of the other brands will not dig in as good.
 
Wow bob, you were really far out. Most of the anchorage area was 25' or so. Please tell me that you weren't throwing your anchor like most of the boaters were! I had to rescue 2 boats that fouled their props with their pwn anchor lines. If Flutog comes back I won't be going!
 
Thanks everyone...I measured my chain today - its a little longer than my original post at 8 feet. Maybe still not enough. I may look at a heavier anchor too.

All good advice - because of congestion I don't think anyone had a 7:1 scope out yesterday.

Phillyteach - That channel is very wide by the bridge 55+ feet and boats were lined at least halfway across the river. Where were you?
 
I have a 13 lb. danforth in a 28' boat. I have a heavy 6' coated chain and a med. weight 10' chain added to it.
I never have any issues with it holding, but I don't normally anchor in water that deep.
The 13 lb. anchor came from Chris Craft, original to the boat. So did the 6' heavy coated chain. I added the
extra 10' of chain cause I sleep on the boat quite a bit at anchor. I like the comfort feeling knowing the
anchor will hold good.
The water bottom has a lot to do with holding also. Where we boat, most of the time the plow anchors don't always
hold near as well as the danforth type anchors. We have anything from soft mud to hard blue clay. No rocks or grass.
 
I was all over. Almost willing to bet good money you saw me at least once. I was the Coast Guard Aux boat working the event.
 
Anchoring w/o someone to assist can be a real challenge! I suggest you get a windless with a remote switch at the helm. Then you can control the boat while the rode is paying out. And it sure is easier to bring that anchor back onboard!
 
I agree you don't need 400+ feet of rode. More chain and a larger anchor should be the answer.

I don't agree with your needing a windlass. While it may make it easier to retrieve the anchor, at that depth and in a current you want the anchor to free fall fast. And with many small boat windlasses you can't do that easily.
 
one problem with danforth pattern anchors is that they can sail in a current so if you are backing down, into the current, they may not dig or even hit the bottom.
 
quote:
Originally posted by pdecat

one problem with danforth pattern anchors is that they can sail in a current so if you are backing down up current they may not dig oreven hit the bottom.
Click to expand...


This is true and it's a known (for some) problem with the lighter Fortress aluminun anchors.
 
If you are frequently anchoring in deep water I would suggest a lot more chain. I have all chain and have rarely failed to set with my fortress even in 60 feet of water in a strong current with 150' chain out.
 
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