“We checked that spare magazines were ready to pull out. Pick them up the wrong way and you waste a precious second or two turning them around. Put them in your belt kit with the curve the right way up, and they’re ready to slap into place. A lot of people put a tab of masking tape on the mag to make it easier to pull out. When my mags were empty, I’d throw them down the front of my smock for refilling later. We could use the rounds from the belts of the Minimi…” Andy McNab, Bravo Two ZeroVertx has some new options available for admirers of their original smock (to wit: offering them in black and dark earth so you can wear one without looking like you're hunting muj or training to be a mall ninja). If you're not familiar with the Vertx smock, it's billed (fairly accurately) as a wearable go-bag.
The smock has 14 total pockets with 6 integrated 30-round magazine pockets. It features NanoSphere treatment of lightweight Cordura (not nylon as their catalog says) so it's weather resistant. Both the hood and the hand warmer pockets are lined with hydrophobic fleece so they won't retain water once they get wet (which is for me particularly annoying and occurs frequently on some garments' front pocket). It's oversized so you can wear it over your other kit, has pit zips with mesh lining to keep debris out while allowing the garment to breathe and features patch/ID panels on the sleeves.
The Vertx smock has been around for a little over a year now and is essentially a modern take on a military classic (the Denison smock, which really is a classic):