The problem ground - Rock and soft mud!

Anchor Features

Marine anchors are manufactured and sold for all manner of reasons apart from the task they are intended to perform. They are made to be cheap to buy or designed to be the right size for the anchor well or bow sprit. They may be light for their size, easy to handle or use a coating that doesn’t scratch. 

All these desirable features, are however, a complete distraction from the whole purpose of an Anchor, which is to stop a vessel quickly and keep it where it is. Any feature of an anchor that does not deliver stopping power or make it easier to retrieve, is wishful thinking for the sake of convenience!

Problem seabed's

Few anchors generate HOLD in soft mud and there’s a high likelihood of getting an anchor stuck and losing it to rock. It's the very soft and the hard ground that cause problems.

The best anchors in soft ground are twin fluke Anchors, simply because they fall correctly and orientate themselves the right way. And weight for weight, they usually have a larger surface area, increasing drag.

Single Fluke Anchors

The reason single fluke anchors perform poorly in mud is because they use a shallow angle of attack to bite in and usually don’t dive deep enough to find harder ground. Single fluke anchors are also prone to turning upside down in mud, because the shank sinks first and the upper surface of the fluke becomes a parachute, helping maintain the inverted position under load.

Single fluke Anchors can often be pulled through mud without biting in. This happens because the underside of the anchor is  pushed upward by harder ground underneath the anchor and mud moving over the rear of the fluke lifts the tip, so the Anchor planes along without taking HOLD. 

This picture shows how a single fluke anchor can ride on its back in mud due to the weight of the anchor pushing down on the shank, turning the shank into a fin that creates a furrow, preventing the anchor from rolling.

Anchor testing

Like most anchors these plastic anchors perform quite well in sand and medium density ground, but do not perform well in soft ground and are almost useless on rock. They also need a minimum of 2 m of chain to be effective, so handling them from a Jet ski is difficult. And the weight of the chain negates the weight saved using plastic.  The inability to easily remove material from the pocket creates another drawback.

Danforth style anchors can hold well, but as the tips of the flukes are close to the shank they tend to roll easily and have trouble resetting.

The following tests, although basic and random in nature are highly effective at showing the real-world effectiveness of Active Anchors against, what are considered by many, to be the best anchors on the market. All these tests are performed with an Active Anchor of lower weight.

In soft and medium density ground these tests show the outstanding ability of an active Anchor to reset after being pulled from the ground.