Okay hold on a second. I keep reading about how stainless steel is unsuitable for use below the waterline. So how come I see so many stainless anchors?
My guess is that aluminum is considered too light... my current anchor is a fairly large but aluminum fluke, and it's surprisingly tricky to set. Also I wouldn't trust it under heavy load, especially after a wind shift; if it holds, the torque would probably bend the shank.hmm, so if stainles is so poor under these conditions what about aluminum?
"Too light"It is too light to set well in many conditions... it is also not as strong as a steel anchor in many cases, and can fail if the load is applied to the anchor from the wrong direction.
The 20lb alu anchor is lighter than the 20lb steel anchor, then?
Two excellent anchors are the Rocna and Spade (Rocna being rather too expensive), available in both steel and alu, and I doubt that any of them are troubled with stress.
Sorry, SD, I was imprecise. You're right about Rocna, of course - but there are quite a few reasonable copies about.There is weight and there is density... the Aluminum anchor's effective weight under water is far less than a steel anchors, due to the lighter density and greater volume of aluminum. Also, the greater surface area of a light aluminum anchor, like the Fortress, often means that it will "kite" if the boat gets moving at all, and not reset.
BTW, can you show me where on the Rocna site they offer an Aluminum anchor. AFAIK, they don't and never have.
The only real copy of the Rocna, AFAIK, is the Manson Supreme, and I don't believe that is offered in aluminum either.Sorry, SD, I was imprecise. You're right about Rocna, of course - but there are quite a few reasonable copies about.
The Fortress actually suggests you shouldn't have too much chain on it, as may interfere with it setting properly. IIRC, they only recommend up to 15' of chain or so... not the boat length or two that is generally a wise idea and what I recommend.More important: I wasn't considering the Fortress as the main anchor - to me it is OK as No.2. And the point about weight wasn't literal - I mean to say that you choose the correct anchor - size, weight - for your boat, material already calculated. A great deal of the weight tends to be added in the chain, and the most common mistake is to leave too short a chain in the water.
The next gen anchors, like the Spade, Rocna, Manson Supreme, etc, are far better, IMHO, under most conditions than the older designs, like the CQR, Bruce, and Danforth.People should pay more attention to anchor shapes and less to weight unless you anchor on some fairly specific bottom surfaces.
I heard this a number of times but I haven't seen any tests that actually show this happening. I can see the flukes jamming but there are many ways for many anchors to fail. As it stands, in most tests Fortress does not let go at all so really they don't seem to have a chance to try and re-set it.My problem with the Fortress isn't its holding power...but its inability to reset reliably, especially if the flukes get jammed.
I heard this a number of times but I haven't seen any tests that actually show this happening. I can see the flukes jamming but there are many ways for many anchors to fail. As it stands, in most tests Fortress does not let go at all so really they don't seem to have a chance to try and re-set it.
At the same time, if anchor sets so easily (as Fortress seems to be) - why would it have trouble re-setting (unless jammed)? And what is a frequency of jamming?