The Mercury, in various guises, has been a staple at the lighter end of Mammut's footwear range for some years (we reviewed a predecessor back in 2011). With the not-so-snappily named Mercury Advanced High II GTX they've beefed things up a bit for a more supportive and protective ride. The result is an excellent waterproof-lined three-season all-rounder that suits a fair range of conditions and terrain.

Since these are a good UK summer boot, I packed them for a holiday in balmy Devon and Cornwall. This may not seem the most rigorous environment to test footwear for hillwalking, but anyone who's familiar with the more challenging stretches of the South West Coast Path will know that it can give many mountain days a run for their money. Over a couple of weeks the Mercury Advanced (etc) have been seen a bit of everything, from steep coastal trails to long stretches on tarmac lanes, bouldery shorelines, soggy woodland walks and muddy cow-churned fields. The weather's been a mixed bag too, with downpours and chills one day and baking sun the next. It's been a short-term test, granted, but so far the signs are good.  

Uppers

Typical of lightweight walking boots, the uppers are a mix of leathers (in this case nubuck and suede) and synthetic materials. The number of stitched seams is not excessive, and since stitching is often the first thing to wear out or leak on a boot this bodes well for the Mercurys' durability. A series of raised rubber ribs are cleverly bonded to the outside of the boot to give the upper some lightweight structure. The ankle cuff comes fairly high, giving plenty of protection against sprains; but with cut-out sections in the leather on both sides to aid ankle flex and a bit of stretchy give in the top inch or so, the cuff doesn't feel too clumsy or restrictive. The padding around the top is on the thick side, a bit excessive perhaps, but it has a nice feeling of softness and stretch. The metal lace eyelets have a robust feel, and with two sets of locking hooks it's easy to fine-tune the fit.

Inside

The Mercury Advanced High II GTX is lined with a waterproof, breathable GORE-TEX Performance Comfort Footwear membrane. In the past I've been sceptical of waterproof membranes in lightweight summer footwear, which I've sometimes found hot and sweaty despite manufacturer's claims to the contrary. But the breathability (or otherwise) of a boot is down to the other materials in its construction as well as the membrane, and in this case Mammut have done a good job. I've been out walking hard in mid-twenties tempratures without noticeably sweaty feet, and while the Mercurys would not be my first choice for a desert trek they offer a sensible balance of waterproofness and breathability for typical British hill walks. They have been ideal for this wash-out summer.    

Sole

There's plenty of lateral stiffness in the sole, which really helps support the feet when you're out on rough terrain or carrying heavy loads (in my case kids; it could as easily be an overnight backpack). At the same time the nice springy flex at the toe end makes for a natural walking feel, not at all clumpy. A spongy shock-absorbing misole soaks up a good pounding if you're out on hard surfaces. At the forefoot end the amount of padding feels spot-on, but to me the depth of cushioning at the rear seems excessive, particularly where it extends beyond the heel of the boot in an odd-looking ledge. When scrambling, which in the context of this test has meant clambering along bouldery shorelines to approach crags, the underfoot give is a little spongy and imprecise; however the converse of this is that on hard-packed trails and tarmac these boots are very forgiving. For secure purchase on a variety of surfaces the Vibram outsole has good deep-ish lugs. These have an unusual slightly concave shape, and the resulting raised edges of the lugs seem to bite well into soft ground. At the heel, meanwhile, there's a decent ledge for downhill grip. One thing that does bemuse me about the sole is an arrangement of flexible rubbery ribs among the more conventional tread pattern. Mammut say they are 'proven', but I can't honestly tell what role they perform, other than to be manifestly less hard wearing than the rest of the outsole (I don't fancy their chances on scree, for instance). 

Fit and Feel

Here's where things get subjective. When it comes to fit I can only say what works for me, and as it happens these boots are spot on. With a generous width and depth at the toe, there's plenty of room for my broad-toed feet. There's space to accommodate a bit of foot spread over a long day, which is particularly welcome in hotter weather. Cushioning along the instep gives these boots a soft comfortable feel, while at the rear, although the heel is not the tightest or most aggressive I've seen, padding holds the foot snugly in place without putting pressure on the achilles. While they may not qualify as 'ultralight', at 1492g per pair (size 12s on my kitchen scales) the Mercury Advanced High II GTX is certainly not heavy on the foot, especially considering its general robustness.

Summary

For its relatively modest weight this is a well-cushioned and supportive boot, ideal for long days out in a range of settings from low level country rambles to the fell tops. Waterproof but not too hot, they are a competent all-rounder for the varied conditions you'll encounter in a typical British spring, summer and autumn. For scrambling, prolonged use in the roughest mountain terrain, and trips above the snow-line look elsewhere - but for anything else the Mercury Advanced High II GTX are good to go.   

Mammut say

"Based on the successful Mercury/Nova GTX, the Mercury Advanced High II GTX Men and Nova Advanced High II GTX Women are cut slightly higher to provide greater strength and safety."

"High-quality materials: nubuck and velour leather, Soft Shell, EVA wedge with integrated Mammut Rolling Concept and sliding lacing."

"Also featuring the scale-like arrangement of the vibram Scale sole, liquid rubber protection at the tips and the functional GORE-TEX Performance Comfort Footwear membrane."

 

• Mammut® Feet Map: targets zones that sweat, feel the cold and are pressure-sensitive, and locates cushioning, warming, cooling, slip and non-slip lining materials, in all the right places.
• Memo Foam: premium quality foam cushioning with excellent elasticity, used for instep, shin, and ankles
• Scale Technology: scale-like arrangement of the lugs, with the proven flexible ribs, on this hiking sole ensure maximum grip on all kinds of terrain and rounded, gentle rolling motion.
• Rolling Concept: patented Mammut sole concept with customised support and cushioning to support natural foot roll, and thus prevent fatigue and avoiding twisting.
• Liquid Rubber Protection: zones featuring Liquid Rubber reinforcements safeguarding the footwear against abrasion and damage. This rubber is applied when wet and is lighter than conventional rubber rands.
• Sizes: Men 6.5 - 13 Women 3.5 - 9
• Weight: 1492g per pair size 12 (my figure)

 

Price £165

More information Mammut website