line for sentinel

[jasonr575]

i have a bronze sentinel to use on my boat which is a morgan OI. The boat is 37 ft long and weighs about 9 tons, i use a 45 CQR anchor (i may convert to a 35lb cqr this year). What size weight should i use and what kind and size of line is recommended. i dont think stretch will be important just strength. As far as the weight i read somewhere that 1lb for every foot of boat length is recommended. If so that is like throwing out another anchor. I was hoping to go with something like a 20 lb rubber coated mushroom anchor so i can use it on my dinghy as and anchor also. Any comments/suggestions?

[camaraderie]

Sentinels are fairly useless when you really need them (i.e. in a strong blow when the rode becomes effectively a straight rod) IMHO. They can be of help in short scope anchorages in average weather but you are far better off with an anchor that will do the job itself.
A 45lb. CQR with a decent amount of chain is plenty big for your size boat....(say 25-50 ft. of chain) assuming you are not headed south. (If headed south get 100ft. of chain due to coral chafe.) If you are having problems holding with a 45lb CQR...I would suggest it is because of the anchor design for your cruising grounds.
OI's have a lot of windage and tend to sail at anchor so if you are thinking about a lighter anchor I would encourage you to think about one of the newer designs like Spade/Manson/Rocna/Delta that will really set and hold more reliably than a CQR. If you decide to keep the CQR...you might consider a Fortress as a secondary that will catch in conditions that a CQR typically fails in (gooey bottoms).I say this as a well experienced CQR owner whose 60lb CQR sits as a secondary anchor!

[sailingdog]

I'd second everything that Cam said and add that some of the newer next generation anchors are quite good. I have 15kg Rocna on my boat.

[Craig Smith]

Third'ed... and here's some math to illustrate just how pointless a kellet is:

This is a somewhat extreme example. A 33lb kellet on what might be used on a 40' boat. Even with a comparatively small 300daN force on the rode it can be seen that the kellet contributes hardly any benefit...



At a more serious 1000daN (serious winds), it is totally useless...



On a 40' boat you might use a 20Kg anchor. Considering the Rocna 15 and other similar sized new generation anchors have been proven to hold well in excess of 1000daN at less scope than this scenario (6:1), it should be clear the kellet is a waste of time.

This is not to say that kellets are entirely pointless; they serve other purposes. However, they do nothing to improve the ultimate holding power of the anchor.

Now consider how much benefit you might get by changing your anchor type, and also upping the size if you wish.

[Meridianpassage]

I have read reports on the merits of the anchor buddy by Craig Smith from Rocna Anchors and also the computer simulations done by Kellet Weight. I am amazed at the negative comments slanted toward this device (Anchor Buddy) from people I gather have never used nor had the "out there real experience. We have carried an Anchor Buddy aboard our sailing vessel " Meridian Passage" a 20 ton sailing cutter rigged Whiting 45 since 1995.. We purchased an Anchor Buddy in 1995 at a boat show in Auckland NZ. I was very skeptical as to whether this device would perform as advertised but was keen to see for myself if it was worth the extra weight carried aboard our cruising yacht. As all cruisers appreciate extra weight is something that just grows as time goes by so unnecessary weight is a no no.

I am a very keen scuba diver and observed, in the first six months, the actions of the anchor buddy at work underwater. This was at varying depths in ALL sorts of conditions in and around NZ. I was absolutely sold on the merits of this device. In my opinion it performs better than advertised for our fin keeled yacht with a displacement weight of 20 tons. The optimum depths for best performance we feel start at 4-5m and get better as we anchor in deeper water.

Without the Anchor Buddy, anchored in a bay where the wind has started to blow strong and a lift/chop has developed our boat tends to sail a bit on anchor. Also when limited swing room means limiting the scope possible for safe anchoring without the risk of dragging, deployig the Buddy in these same conditions we are very stable. When observing the action going on under water this is what I see - the Buddy in 5m depth hanging about 1m up from the bottom keeps the chain close to right angles to the boat leaving the chain to the anchor laying on the seabed. In many of my observations I note there is absolutely no pull on the chain between anchor and Buddy The effort of the motion of wind and sea state trying to straighten out the rode with the Buddy hanging off the rode keeps the rode in most cases at between 60-90 degrees and I firmly believe doubles the holding power of what I have set.

My wife and I have circumnavigated New Zealand twice. We left NZ in 1998 and cruised parts of the Pacific islands and then to Australia where we sailed from Northern Queensland down the coast to Tasmania. We circumnavigated Tasmania and then sailed across the great Australian Bight to Western Australia and up that coast to Dampier. We set sail for S/E Asia and Japan spending a total of 5 years in this area. We are currently in Alaska. I only mention all this to give you the reader an idea of our experience deploying the Buddy and of the areas we have cruised. . Many, many times we have said thankyou, thankyou Mr. Buddy for holding our yacht safely in conditions that without this devise we know we would not have held and would have had to move. As those of you who are out there appreciate moving anchorage is not always the safest option.

Our most recent experience with Mr Buddy was here in Alaska in a Bay we felt was well protected and we had planned to stay for a couple of days. It turned into the bay from hell as the wind started to build with the seas becoming very choppy. We started dragging and because it was near evening and we did not really want to move on we thought maybe this would pass. NOT SO!. We let out more scope, we were anchored in 8m of depth with an initial scope of 4-1 I increased this to 5-1 and deployed the anchor buddy. I had not bothered deploying the Buddy on arrival as this was a beautiful calm bay. The change in the boat was instantaneous and never fails to impress me. No more sailing around NO drag and a real sense of safety. However the wind did not abate in fact it escalated dramatically to the point we felt no longer safe here.

MP still held fast but definitely time to move. Crawling forward almost on hands and knees as the wind was so strong I proceeded to retrieve Mr Buddy which thank goodness is very quick and easy to do despite its weight. With the Buddy back on board the anchor immediately started to drag with the extreme wind conditions and always the most destructive failure to anchor dragging is the wave motion which when building, lifts the chain from the seabed closer to the anchor and has the affect of less scope ratio and plucks the anchor from the sea bed. The buddy I am certain helps to maintains a true and reliably scope ratio in these adverse conditions. We finally weighed anchor and sailed through the night to another Island in the Aleutian chain. We discovered when leaving this bay that the wind funneled down this bay and once out to sea conditions were calm in comparison. A lesson learned regarding local geography and wind effects in bays here in the high latitudes of Alaska.

I am always amused when reading reports like this one of Alain Fraysse about a computer simulation of a devise that to me reads they have actually never been out there in the real world and experienced what this devise "Anchor Buddy" can do. To me, theorizing about the merits of any devise compared to actually getting out there and experiencing the practical use of a devise of any nature is totally unfair comment. We have been continuously cruising for 12 years now and rank the Anchor Buddy as safety equipment aboard our cruising yacht in parallel with our - liferaft, Flares, Sea Anchor etc and when all else fails a bottle of whisky to end on a high note!

We have a 65lb Delta, and a second Delta of 45lbs and also a 65lb Swabric fisherman style anchor for weed/kelp bottoms. I am not interested in the discussion/merits on the best anchors out there in the market in this forum. The anchors I have together with Mr Buddy are more than enough for our peace of mind. The only comment I will make here regarding anchors is that in our experience over the last 10-12 years we have seen all types of anchors with the owners readily admitting to anchor failure at one time or another. To start spouting about my/your anchor being the best on the market – forget that rubbish, find an anchor that works for you with minimal failure and I would suggest you have just about got it right. I say this as our experiences have led us to believe there IS NO bullet proof anchor out there.

No matter what anchor you deploy we believe the use of an Anchor Buddy will double the holding power. That to us is a great peace of mind and can only be good for any cruiser out there.

Anyone wanting further discussion with me regarding the merits of an Anchor Buddy feel free to contact me at (I am unable to add this here according to the quick post) but remember we are now in Alaska and Internet is very limited so replying may take some time.

[Craig Smith]

The implication, Meridianpassage, of what the community may conclude from your multiple postings of the identical diatribe, by a new member, and bouncing a number of threads across SailNet (most of which are a number of months old), is not positive. From my perspective in light of recent protests courtesy of Anchor Buddy Ltd, its cause is quite obvious.

That notwithstanding, I'm not sure what the argument is about. The correctness of your belief that the Anchor Buddy will "double your anchor's holding power" is obviously entirely dependent on the anchor in question, not to mention the scope being used and the ultimate resistance provided by the seabed at the time. The fact that you state this belief but state neither the tested holding power of the anchor alone, nor even what it is, sounds very similar to the illogical claims in Anchor Buddy's marketing material, and speaks volumes.

Nevertheless, we can conceed that if it (the anchor) is a 2lb brick, then this may be the case and your belief is well founded. If the anchor is a sensibly chosen and well sized model according to accepted standards of seamanship, it is most certainly false and you are seriously misguided.

Catenary equations are not difficult to comprehend nor solve. The simulations above are achieved on a very simple Excel spreadsheet, and the math is well established.

Gravity is just not that powerful, and a heavy weight added to one's rode does not do a whole lot when large forces are present in that rode. It is difficult to argue with physics.

This thread in particular does not reference my article on kellets, so I will expand on the topic by linking to it here for those that are interested:
www.petersmith.net.nz/boat-anchors/kellets.php

[sailingdog]

Meridian-

It really isn't kosher to post the same post to multiple threads.. especially if it is within minutes of each other.

[camaraderie]

MeridianPassage testimonials and his name are on the Anchor Buddy site so I see no reason to question his integrity Craig. On the other hand people believed the earth was flat but that didn't make it so. The physics are quite apparent and a weight on a bar tight chain makes no difference whatsoever...and yes Meridian...I know from experience what a bar tight chain looks like. A 5:1 rode on a Delta (which I use) is totally inadequate. 10:1 in storm conditions gets you 91% of horizontal holding power.
Kellets are useless except to reduce your swing circle in light winds.

[erps]

5:1? 10:1? Geez, I feel like a hog when I use 3:1 up here in the PNW. Of course it always gets real interesting when the wind starts blowing in anchorages.

FWIW, I was a kellet user when we were in small boats with limited anchor size and limited amounts of chain. On calm days, we actually swung circles on our kellet, rather than the anchor. One time while stern tied to shore the wind came up and I watched as our kellet nearly rose to the surface each time a gust hit. That was the light bulb moment for me when I realized as previously mentioned by Cam, that when I needed holding power the most, the kellet was giving little benefit. I might revisit kellets if it helps keep the boat from sailing back and forth as MeridianPassage observed. "Nikko" seems like a dog anxious to go for a walk when anchored in the wind.