A box anchor is a beautiful tool to have in the boat. Chain is not used with a box anchor, the heavy steel bar takes the place of chain, and it will only end up fouling it. The exception to this is in large ocean swell, where the constant rise and fall of the boat in relation to the bottom causes the rope to lift the control arm of the box anchor over 45 degrees, and that can unearth the anchor. In a lake or even the ocean without large swell, it isn't anything more than a hindrance.
Like jdonalds said, it is possible to find conditions that will cause an anchor to unearth as well as the Richter anchor is also a set and forget anchor. And a Danforth style anchor is a fine anchor, if it is matched to the boat. The one Yamaha sells is NOT matched to the boat and is much too small and light to be a very effective anchor. And as a very cheap fluke anchor, it is hard to set in many conditions. But larger danforth anchors with better fluke control won't fit in the boat well. Fortress makes a great Danforth anchor, again it won't fit. Danforth anchors all use chain to keep waves and boat drift from lifting the shank, which can unearth the anchor.
I modified the box anchor design to fit and hang securely in the '07-'09 SR/AR/SX 230 and the 232's that fall in the same year. I took that design and built several prototypes, until I found a design that was good. I built 48 of them since 2009. I retired from making them due to lack of interest and restrictions from advertising them. They went pretty much by word of mouth. Again, they only fit the above boat, not any of the others. All of the others, you can just use the folding box anchor, which is a great anchor! I am pasting my box anchor instructions below if your interested...
I know you will love this anchor as much as me. You can experiment with setting the anchor but I find that just throwing it in upwind as the boat is slowly drifting away from where I tossed it is the best way to get a slow but deep set. When I have tried to power set it, your speed is such that it tends to bounce on the bottom instead of digging. But even if you power set it, it will dig in within 15-20 feet or so (but you will have twice the mud to get off of it!). Slide Anchor says 2 to 1 scope. I find about 3 to 1 works better or the rope entering the water at about 45 degree angle or so. The anchor tow bar works like a chain and a chain isn’t normally needed. But in the ocean with swell, you may want more scope and possibly chain. You will need to lower the anchor slowly to keep the chance of the chain fouling the towbar or the anchor to a minimum. But the only reason to use a chain with this anchor is to keep the swell from lifting it. You won’t use chain in lakes or bays or even in most ocean conditions. Also, when the wind shifts and the boat pulls back across the anchor it will lift it and reverse it, resetting on the opposite flukes. You will have a bit of mud on the flukes when it comes up. I generally tie the anchor line to a cleat, hanging about 10’ deep and move in forward idle for 2 to 3 minutes and it comes up clean. Be careful, when I have tied the anchor off too shallow, it has bounced off the hull (especially when forgotten about and I took off with it dangling!). I also use a stainless swivel on my line between it and the anchor and it helps tremendously.
This anchor and draw bar are Hot Dipped Galvanized, it is very tough and acts as a sacrificial anode, just like the zincs on your boat. It will wear and you will need to protect it. So you will have to get a little touch up paint if you want to keep it from showing rust as it wears. The Hot Dip Galvanizing company said to use cold galvanizing paint on it to keep it touched up anytime you see a scratch or any rust forming. Rustoleum makes zinc rich cold galvanizing spray as does a number of other companies. I do not know if it is available at your home center but it is available, you may just have to look for it. It is not just silver paint, it contains a high percentage of zinc. Nothing is rust proof except for stainless steel, so keep it touched up!
Pad your anchor locker or where ever you store the anchor. It is heavy and if and when you bounce across waves, if that heavy anchor bounces, those flukes will crack your floor or hull. Be sure you tighten the shackle thumb screw with pliers real good after you secure it to the anchor tow point. You can safety wire it if you so choose. You should consider getting a stainless steel swivel rated at 1500-2000 pounds, it will keep the rope from twisting! Sorry for the lengthy letter, but I wanted you to have all the info that has taken many sets of this anchor to learn about.
... OK...uh ummm thanks.
