Angling Designs offers their Small MRT Box (6.25" x 4.25"x 1.5") for freshwater and small saltwater flies. Like the Large box, this box is molded polypropylene and feels bombproof in your hands. Price: $39.95.

TAKE A LOOK at the fly box pages in any big outdoors catalog and you'll quickly discover what retailers think are the features most important to fly box purchasers: the ability to hold many sizes of flies securely, lightness and durability, organization and display, and fly protection and preservation. Those last features have been the most recent focus for manufacturers, who have identified "waterproof" and "rust-proof" as the key catch-phrases. It is, like so many other things in fly fishing, technology grabbing hold of our senses.

But devotees of Walgreen pill boxes scratch their heads when someone suggests that they pay more than $5 for a fly holder. Everybody likes dry, sharp and rust-free flies, but that's what a vest patch is for, right? Like other trout anglers, I rely on a very simply system: cheap clear boxes for flies in the vest, a foam vest patch to rest the weary, and a moderately expensive fly box to organize recently tied flies and holdovers. My used saltwater flies get hung on the gunwale carpet. Not surprisingly, my habits are reinforced by the practical results of what I do. And like others, I know what I like in a fly box — until I see something better.

When we first looked at the Dry-Tech MRT™ Box, we were skeptical that the whole notion of drying flies or keeping them dry would motivate us to change our fly-storage habits. Our skepticism was somewhat reinforced by the fact that both the MRT boxes felt heavy, even though we are talking in terms of ounces here. (Somewhere in the back of our minds, the notion that lighter equals better is firmly established.) But then we were reminded of the fact that our cameras have never lived anywhere else but in Pelican Cases — bulky, un-storage-friendly, and absolutely essential gear as far as we are concerned.

We knew we needed some field experience to help form an opinion, so we contacted veteran guides John O'Hearn, who's used his MRT in the Keys for several months, and Dec Hogan, who's been happily stuffing an MRT with wet steelhead flies. Dec says the box is remarkable for its ability to dry big wet marabous. John says he now considers the box a key part of his system for drying and storing permit flies, which are among the most time-consuming patterns he ties. Interestingly, both consider their boxes places to store flies on the boat, not as vest or fanny-pack items. And both rave about the utility, especially as a place to store and revive used flies.

The Large MRT Box (8.75"x 5.0"x 1.75") uses slit-foam to hold flies. It does sacrifice some space in order to accommodate two desiccant packs, but we found there was still plenty of room for flies. Price: $44.95.

Our next questions had to do with the Crystal Container desiccant packs the MRT boxes employ to remove moisture. Did they work, and were they practical? We put a bunch of soaked bonefish flies in the smaller box, closed it, and left them for two days, and sure enough, when we retrieved them they seemed completely dry. O'Hearn and Hogan corroborated our results. The desiccant crystals absorb water for a few days prior to turning green, which means that the crystals are losing their ability to absorb water. At that point, you remove the pack, pop them in the microwave, and they're back to full strength. Easily done. If you're wondering where you might find a microwave in the wilds of Patagonia, Angling Designs offers the Crystal Container packs as separate items, so you can buy an MRT box and a couple of extra packs and forget about civilization altogether. Interestingly, we found that the packs continue to suck up moisture after they turn green anyway, but it's probably not a bad idea to take extras, especially if you are changing flies often.

So the final and more important question was this: Would we change our fly storage habits to make room for a $40 or $45-dollar box that required us to nuke the drying element every week or so during fishing season? Visions of rust spots around permit, bonefish and tarpon flies, and memories of tiny midge hooks dulled by corrosion, told us Yes. Unless you're fishing with $5-a-dozen flies, the expense is easily justified. If you take special pride in your salmon flies or spend an hour tying each of your permit crabs, a box like this seems a very good value indeed.

There are other waterproof fly boxes on the market — Scientific Anglers' System X, Orvis's Watershed, and C&F Design Waterproof boxes come readily to mind. These boxes are lighter, and they're comparable in price or a little less expensive. But none is designed to dry wet flies. And of course a little wet is as bad as a lot wet when it comes to fly storage.

Our overall take on the Dry-Tech MRT's is that they fill an important gap in fly storage offerings, in part because they make us think differently about what a fly box is meant to do. We don't think they'll replace ultra-light-weight fly boxes meant for the vest or fanny pack. But the good news is that you can easily complement a solid storage box like the MRT with inexpensive fly containers and have the best of both worlds.