|An Australian company called CGear, an auspicious name for possible sea kayak use, makes a product called Multimat that claims to "move sand down under" to provide a sand and dirt free camping sites. The video on the site (http://www.cgear-sandfree.com/) shows sand disappearing through the mat as if by magic. Since I spend a lot of time camping on sand and fighting a generally losing battle to keep it off of me, my gear and, most distressingly, my food, CGear's Multimat caught my interest.
I ordered an orange mat in the smallest of the three available sizes of six, eight and ten foot squares weighing three, six and nine pounds respectively. There is a brass D ring at each corner and in the middle of each side along the nylon taped edges. The mat comes in a 16"x18"x4" beach bag made of the same material as the mat. The mat is bulky compared to a tarp of the same size because of the unique weave of the fabric that allows the mat to function. For many applications such as caravan or car camping, this size is of no concern. With the limited space of a loaded kayak, it is a consideration. The weight of the mat makes it's use for backpacking impractical.
I spread the mat out on the sand above the high tide mark on the beach near Cape Hatteras, North Carolina. I tested the claims about sand falling right through the mat and not coming back up through it. I was greatly surprised when it worked perfectly. The sand that poured out of my hand onto the mat disappeared immediately through the open weave of the fabric. I shoved hard on the mat, stomped up and down on the surface, sat on the mat, rolled over on the mat and no sand appeared. The claims of the manufacturer were true! A sand free surface on the beach!
Next I took the mat down to below the high tide line where the sand was wet. Here is where things started to go wrong. Wet sand clumps. It doesn't fall through the weave like dry sand does. It just sits there. If you wait until the sand dries in the sun, then it goes right through with a brush of the hand. When it is wet and you brush it over the weave however, it just sticks in the weave and does not fall through. You can pull up the mat, shake it hard and the sand just stays in the weave.
Now if I was kayaking along the shores of the Nullarbor on our driest continent, this mat would work perfectly all the time. However, I paddle in wet conditions frequently, camping on marsh over soaked ground and frequently mud. Mud oozes up into the weave of this mat leaving you with a quarter inch thick by 36 square foot sheet of structured mud. Vigorous cleaning in the water gets rid of only some of it, but it will not come clean without a hose. With the mud in it, it is heavy and very dirty getting back into the hatch of the kayak.
The mat would make a great ground sheet under the tent on porous ground as the thickness would protect the tent bottom from stones and sticks and rain water would fall right through. But if the problem is wet ground underneath the tent, water would also come up through the mat and a standard ground cloth would be better. If there was only room for a tarp or this mat, I would have to take the tarp. But this mat has won a place in my car whenever I am going camping to a dusty or sandy place.