Anchoring, Chain Only

[ScituateMan]

Hi,

I recently returned from a ten day charter in the BVI. Had a wonderful time with nine people aboard a 47 foot cat.

I have an anchoring question...

This was the fourth time I have chartered. All previous charters had some length of chain and a lot of anchor line. The anchor line was always marked at 10 foot intervals. I would always put out 5 to 1 or more of total anchor line. Would reverse and set the anchor. This boat had only chain and not a whole lot of it. Any time I anchored, I would try to set the anchor with some reverse engine. The anchor would never grab solid. Is there something I should have known?

[Bene505]

Can you say more? How long was the chain? How deep was the water? And how high above the water was the anchor roller?

Regards,
Brad

[Craig Smith]

How the anchor sets isn't really affected by the make-up of the rode; if anything, chain should be slightly beneficial. It sounds like you didn't have enough to get adequate scope but without more details it's guessing.

[oceanscapt]

It might be that you were backing down too fast. One of the virtues of nylon rode is that it stretches and the pull on the anchor is a bit smoother than chain.

Did you go to the same anchorages? Did you anchor in water shallow enough for the 5:1 scope to take effect?

[Zanshin]

Most anchorages in the BVI are pretty shallow and have good holding (JVD's Great Harbor excepted on the 'holding'). I think that the charter boats all have 80-100 of chain at minimum. Anchorages will usually be under 30' deep over sand so most anchors tend to hold well and with all-chain even a 3:1 should be sufficient for both setting and holding. I wonder if, as mentioned by oceanscapt, the power of two engines in reverse was just too much. I like to let the wind "set" the anchor and then let out the rest of the scope and then use reverse to check holding - when I've used reverse to set the anchor I've had it skip over the bottom and often have to try again.
Which anchorages did you have these problems in?

[kellysails]

I always let the wind take the boat back and never put it into reverse until I have a good amount of scope out first. Even if the wind takes the boat sideways that is fine. The anchor needs to ease into the seabed. After you get 5x scope out really drive the anchor in with half power in reverse (1500 rpm), but start with a slow soft throttle first.

The more chain you have the better it is. While in Greece we had over 200 feet of all chain and it set every time. It is also interesting to snorkel over the anchor as the helmsmen puts in the final power to set it. You can learn much on how an anchor works by doing that.

-craig

[Saildoggie]

I charter cats frequently in the BVI's and all of them are chain rode only which works very well, the cat should come with 200' of chain which is standard.

A simple set into the wind, backing slowly as you pay out the chain, let it settle, you can reverse at low RPM to see if it is dragging, then add the bridle before any more than 1,000 RPM then back down at 2,000 RPM with the bridle on.
I like to snorkel the set after to assure it is dug in properly.

[AdamLein]

In addition to the "let it settle before backing down" suggestion, another common problem is stopping the boat, dropping the anchor, and letting out all the rode in one go, and then backing down. You don't want a pile of chain sitting on top of your anchor. Instead, let out rode only until the anchor touches bottom, and then let boat drift back as suggested above, paying out more chain as you go. Snub it when you get to the desired scope (or better, snub at a greater scope and then reel a bit of it in after the anchor is set).

[ScituateMan]

Thanks for the info everyone. I forgot to mention in my first message that I didn't know how much total chain there was and it wasn't marked with intervals. It made me think that with all chain all I was supposed to do was just drop it to the bottom. From your replies it sounds like the procedure isn't any different. Zanshin, you mentioned something about Great Harbor on Jost Van Dyke. This is the place that worried me the most. We anchored in 30 - 35 ft, I put out all I had and still dragged when reversing to 1200 RPM. Perhaps 1200 with two engines was too much power (as someone suggested)?

[kellysails]

Hmmm, not sure but you would require at least 120 - 140 feet of chain to meet 4x scope.

On a different note. I learned this trick a few years back from a person who has done dozens of charter trips.
Marking the chain. Use different color cable/wire ties for chain markers. It is really important to know (prior to leaving the dock) exactly how much rode you have in the bow locker and to ensure that you mark it. Using very small plastic cable/wire ties it is fairly easy to mark the rode (chain or rope) using a color coded cable/wire tie system. Last time we used yellow, red, black, white, and green. The black ties were a bit hard to see as the windlass was feeding out the rode. I used about 6-7 wire ties for a mark. It is a hassle to pull all the chain out of the locker and stretch it along the deck to mark it but well worth it. It is also 10x cheaper than the purpose built plastic markers that you can buy from a marine store.

ps - I never cut the ties off after my charter, I also leave the depth key taped to the anchor locker. I assume the charter company does not mind, never have heard a complaint.

-craig