SPADE     How it works...  Simplified

It lands the right way up every single time...

Thanks to the SPADE's unique triangular ballast chamber the anchor is designed to land at the optimum angle for penetration every time (a similar angle to a chisel being used in wood).

...it digs in...

As well as tipping the anchor to the optimum angle, the ballast chamber positions a staggering 50% of the anchors weight directly over the penetrating tip, maximising its ability to dig in. 
The SPADE anchor actually begins to dig in the second it lands on the seabed, in exactly the same way as your foot starts to bury if you stand in a sand pool for a few minutes.  Having the right angle and weight distribution assists the SPADE to penetrate thick weed and kelp, where other anchors would simply slide over the top and gather the weed.

...then holds

Once it has dug in, the SPADE presents its full surface area towards the direction of load - the larger the surface area, the greater the holding power.  Any load sufficient enough to move the anchor will cause it to bury further,  Whereas a convex* blade can pull out with a sudden wind or tide shift, the SPADE's concave blade will remain buried.  A concave blade acts a bit like a parachute under the seabed and continues to remain buried and offer maximum resistance  even when the load is so great that it begins to move.  The SPADE will not pull out during wind or tide shifts, instead it chisels its way around to the new direction.

...and keeps holding... full stop!

There have been reports of SPADEs holding during earthquakes, hurricanes and even Tsunamis.  SPADE anchors are built to withstand enormous loads as they keep holding long after other anchors have dragged.  On the larger sizes** the shanks are fabricated to form a triangular box section to maximise strength without compromising weight distribution.  SPADE anchors are built for optimum performance rather than down to a price and come with a six month manufacturers full satisfaction warranty.***

*Convex blades are found on many anchors such as plough anchors.
**Model 80 and above.
***Conditions apply.