Dual anchoring

[Descant]

In tandem anchoring, what is the recommended scope and or distance between the two anchors?
Thanks.

[SVNeko]

It seems sometimes charter companies just say that as a CYOA kind of thing. Its not an easy thing to do on a cat unless it is set up for it, and most are not. Ours is not, so in the few times we've put out two anchors, and its really only when a hurricane or something similar is threatening, we dinghy out the second one and shackle its rode to the main rode. That eliminates the horrible mess you would get with two leading from your bow with bridles. As an aside, we now exclusively use soft shackles for our bridle and this sort of connection. So easy to use and strong as can be.

[belizesailor]

Originally Posted by ebisucapt

Belizesailor. I didn't feel I needed it really. But Sunsail said to do it and we did as we thought that if the boat did drag and was damaged by going aground insurance might not cover it. We used 2 anchors at Wippari and South Water caye At Hachet caye we were hit with some annoying chop and 20 knot winds and it was recommended two anchors there if mooring balls weren't available. But we did get a mooring ball.

Just for future reference, I don't recommend anchoring at Wippari, its deep and the holding is not very good. If you get into shallower spots around Wippari then you are almost certainly damaging some of the amazing coral that grows there (awesome snorkeling). Pick up one of thier moorings or move on to another place.

No need for two anchors at Southwater. Plenty of good deep sandy patches well away from any hazards.

[belizesailor]

Originally Posted by Descant

In tandem anchoring, what is the recommended scope and or distance between the two anchors?
Thanks.

Assuming you mean "tandem" as in two in line off the bow, there are two ways to do this that Im familiar with.

One, A second anchor is attached to the head of the primary with a section of chain. No convention I know of for the length of this section, but about 15' is common. Pretty straight forward to set...lay them out in line and set hard. Retrieval is a bit more challenging. A trip line afixed to the head of the first, longer than the length of chain, helps.

Two, set two in line on separate rodes. Deploy primary, let out enough scope to get it to start to set (about 3:1). Drop secondary (make sure you don't foul or cross over primary rode) and continue back while snubing and setting them both (extra hands on deck for this helps). Let out extra scope on primary, till you have appropriate scope on secodary. This is not one of my favorite dual anchor configurations, but this, or a variation thereof, is what charter companies sometimes recommend.

[Nicholson58]

We carry a 120 # Rocna which replaced the 74# CQR as primary. The installed secondary is a 54# Bruce. We also carry the old CQR, 35# Danforth, 180# fisherman's. For all of the secondary anchors, we haul them to station with the dinghy. Maneuvering our tank in close quarters is not easy. Secondary may be off the bow or stern and may include anchoring on the beach or in a nearby drop-off. Fortunately, we don't do this often. Nice to have options.

[thinwater]

Originally Posted by belizesailor

Tandem Anchors (in line, single rode). To increase holding power when bad weather is expected (the pros and cons of Tandem Anchors has been already beat to death on other threads...so lets not do it again here).

Not actually, not unless the wind never changes direction more than 5 degrees or unless you are anchored in rocks.

If the wind changes at all, the lead anchor rolls out every time. You end up with less hold than 1 anchor, since the lead anchor was the best one.

In rocks there is some benefit because the second anchor is in a good position to hook something if the front anchor slips off.

I've done a bunch of instrumented testing on this. In-line is for rocks and shingle only.

[belizesailor]

Originally Posted by thinwater

Not actually, not unless the wind never changes direction more than 5 degrees or unless you are anchored in rocks.

If the wind changes at all, the lead anchor rolls out every time. You end up with less hold than 1 anchor, since the lead anchor was the best one.

In rocks there is some benefit because the second anchor is in a good position to hook something if the front anchor slips off.

I've done a bunch of instrumented testing on this. In-line is for rocks and shingle only.

Just describing the technique, not arguing the merits.

[Jim Cate]

Originally Posted by Nicholson58

We carry a 120 # Rocna which replaced the 74# CQR as primary. The installed secondary is a 54# Bruce. We also carry the old CQR, 35# Danforth, 180# fisherman's. For all of the secondary anchors, we haul them to station with the dinghy. Maneuvering our tank in close quarters is not easy. Secondary may be off the bow or stern and may include anchoring on the beach or in a nearby drop-off. Fortunately, we don't do this often. Nice to have options.

??? You manage a 180 pound fisherman from the dinghy???

You be a better man than I, mate!

Jim

[estarzinger]

^^ jim, just let Ann do it. She can handle it. You just provide management direction.

[TOT]

Originally Posted by ebisucapt

I am sorry SV TOT I meant I am hanging my head in shame.

We are always learning my friend (me included) 😃


SV TOT
Wayne 😃

[Jim Cate]

Originally Posted by estarzinger

^^ jim, just let Ann do it. She can handle it. You just provide management direction.

Dang, why didn't I think of that???

Jim

[JPA Cate]

^^Nevair!

Admirals do not deal with anchors! We have minions to do that! :-D! ;-)

ann

[Factor]

Anchors in tandem is not in my experience a good solution. One will set before the other, rarely will you have tow properly set anchors

[ebisucapt]

Originally Posted by belizesailor

Just for future reference, I don't recommend anchoring at Wippari, its deep and the holding is not very good. If you get into shallower spots around Wippari then you are almost certainly damaging some of the amazing coral that grows there (awesome snorkeling). Pick up one of thier moorings or move on to another place.

No need for two anchors at Southwater. Plenty of good deep sandy patches well away from any hazards.

We stayed there because of it's close proximity to the marina at Placencia for our return the next day. There were some shallow area at south end of island with no coral but couldn't get anchor to hold so did have to anchor in some deep water. And yes there was some great snorkeling there and we also dinked over to Bakers Rendezvou. Great over there to. Mooringballs were taken. Greg

[Canibul]

Originally Posted by Factor

Anchors in tandem is not in my experience a good solution. One will set before the other, rarely will you have tow properly set anchors

And the potential for tangles, snarls and aggravation during retrieving them increases. Which increases the chances for gear damage, personal risk. etc.