Mantus M2 Anchor Review - Why we love our anchor

When we purchased Via in the fall of 2020 with plans to move aboard right away and start cruising in the PNW, the first piece of equipment I decided to upgrade was the anchor.  Good ground tackle is crucial for a cruising boat, especially one that is going to be taken long distances and to remote places.  Cruisers depend on their anchors to keep themselves and their floating homes safe, and I wanted to sleep well at night instead of worrying about if we were dragging.

For our Caliber 40 LRC, we ended up getting the retlatively new M2 design from Mantus Marine.  After extensive research, I had originally decided on the M1, but after finding that it would not fit on our bow roller due to the huge roll bar, I ended up finding a 65 pound M2 at the local West Marine just sitting on the shelf.  I was a little unsure of this anchor because, compared to other designs, there were relatively few reviews out there due to its recent release.  I trusted Mantus Marine could design a good anchor, and it was convenient, so I went for it instead of waiting for shipping for another model.

Some of you may be wondering why I bought such a big anchor for our 40 foot boat.  More than any other topic in the sailing world, anchoring seems to illicit unusually strong opinions and passionate arguments.  I’ll leave it at this, Mantus recommends a 65 pound anchor for a boat Via’s size to be used as a storm anchor, and my personal belief is your main bower should be your storm anchor.  I’m sure the 55 lb model would have made us just as happy, but I don’t think the extra ten pounds is ruining Via’s sailing qualities.  For coastal and weekend cruisers, the 45 pound model would probably be sufficient, but for our purposes, I have never regretted going bigger.  

My initial impressions of the anchor were positive.  It was obviously big, but also seemed robustly constructed.  The anchor is designed to be disassembled and the fluke and shank are held together with a single, though very large, bolt and castle nut.  The design of the Spade anchor is similar in this regard, and has been a tried and true anchor for years.  Mantus states that not only is the bolt well oversized for the stresses, but it only carries a fraction fo the load transmitted from fluke to shank.  The castle nut has a large cotter pin to keep it from backing out.  I was worried this cotter pin might get damaged by normal use, but so far this has not been an issue for us.  The galvanizing looked immaculate, and I liked the way the anchor sat on the ground, presenting the tip first to help the anchor dig in.  The M2 lacks the roll bar of the M1 and Rocna style anchor, which are designed to force the anchor to sit upright instead of getting “stuck” upside down.  The M2 instead has wings on both sides of the flukes which help the anchor sit properly for a good set and the weight is concentrated near the tip.  The lack of a roll bar also makes the anchor sit very well on the bow roller of pretty much any boat.  The wings do make the anchor wider than some other designs, and may get hung up on the bobstays of some boats with large bowsprits.  On Via, the anchor rollers are located on the end of the bowsprit instead of the side, so our fit was perfect.  The M2 also has two holes, one in the fluke and one in the shank, which can be used to attach trip lines or floats.

The M2 is designed for boats with bow rollers

One interesting thing to note - during my research I had found one post on a forum that indicated that Mantus was redesigning the shank for the M2 and would be sending out new shanks to all M2 owners.  I couldn’t find anything about this on the Mantus website, and since I had bought through a retailer (West Marine), I assumed Mantus would not know to send me a new shank.  I reached out to Mantus and got a prompt response asking for my mailing address, and sure enough a new shank arrived in the mail.  Mantus told me that the new shank was designed to help the anchor set better in very soft bottoms, similar to what you may find in the Chesapeake.  The new shank was very similar to the old one, just a little longer.  The slight difference goes to show how much thought goes into a good anchor design.  I was impressed with Mantus for sending out the new design to all M2 owners and I find it refreshing to see a company support their customers and back up their product like this.  I will say that I would have liked to see something on the Mantus website about the new shank, both to notify and provide information to owners, but also to explain why the new design was deemed necessary. We got our new shank prior to ever using our M2, so I can’t speak to any difference in performance.  

New vs. Old Shank, with the new shank on the bottom. The subtle change speaks to the thought Mantus puts into its designs.

We have now been using our Mantus anchor for over a year, and could not be happier.  We have sat out gales with winds well over 40 knots, strong currents that change direction with the tides, and a variety of substrates from the sticky mud of the PNW to the white sand bottom of the Sea of Cortez.  I think in nearly 150 nights at anchor, we have only had the anchor not set three times, twice I believe were on a bottom consisting of fist size stones, and once when we fouled on a discarded crab trap.  In all cases we were able to move to a slightly different location and the anchor set the first time.  Whenever the wind or current has shifted substantially, our Mantus has always reset right away, and we have never dragged even as other boats around us did.  Though we always try to pay out enough chain to give us a scope of five to one, we have sometimes had to keep it as short as three to one due to swing room.  Again, our trusty Mantus has set immediately and held strong.  

Now that we are in clear Mexican waters we have the benefit of being able to actually see our anchor, a wonderful change from the cold murky waters of the higher latitudes.  After a recent 180 degree wind shift I dove on the anchor and found it had rotated around and dug back in without moving more than a foot or two.  That is exactly what you hope for and is the kind of thing that inspires confidence in our hook.  

While our experience with other anchors is limited, we now have enough experience with our Mantus M2 to confidently recommend it to anyone in the market. And for full disclosure, though we are now brand embasadors for Mantus, we were not when we purchased the M2 anchor. It was only after our positive experience with the M2 that we reached out to Mantus to try their other products.