Simms G4 Boa Boot Review

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Be sure to check out our current line of Simms Wading Boots here.

The Simms G4 Boa Wading Boot from Simms is one of the most technically advanced high-performance fly fishing wading boots on the market. Simms built this wading boot to last and hold up to the longest hikes through the roughest country and keep anglers on their feet while wading fast, rocky rivers. The innovative Boa lacing system provides support and the ideal comfortable fit while a new traction system provides grip and stability. Durability is maximized with tough materials for an abrasion-resistant design. With all these detailed features and on-the-water performance it is easy to understand why the award-winning Simms G4 Boa Boot took the prize for Fly Fisherman Magazine’s Best New Wading Boot and the IFTD Best New Product Showcase.

BOA Lacing System

The Boa single-wire lacing system has multiple advantages over standard lace-up wading boots. The first is no laces coming untied while you are hiking or wading. With the new Boa Lacing system, on the G4 Boot, with the turn on of knob, the sturdy, asymmetrical wire lace tightens for a supportive custom fit that adjust to foot shape and size. The on-off capabilities are also simplified with this system.  For extended trips into far-off fly fishing destinations or as an affordable piece of insurance that stows in your pack, there is a simple BOA  repair/replacement kit that is simple to install.


The G4 Boa is built for maximum durability and abrasion-resistance.  The tough, waterproof PU leather and synthetic TPU uppers hold up to rocks and miles on the trail and in the river. Additional padding under the uppers further beef up the rugged durability.


Simms added the new Streamtread Idogrip traction platform to the G4 Boa Boot. This soft, grippy Vibram rubber sole has multi-directional lugs so more of sole is in contact with the ground. This minimizes hard, rigid sole materials. Combined with the soft EVA cushioning, this is the basis for the proprioception engineering which simply means you have more feel for what is going on under your wading boot. This makes for quick adaptability, better stability and added traction. For anglers who use studs to further bolster traction, the G4 is stud-compatible with Simms Alumibite and Hardbite Studs. The soles feature red indicator areas to let anglers know the optimal positions to place studs.


As noted earlier, the BOA lacing system creates a wrap-around fit that provides a comfortable fit. The interior neoprene liner adds snug, soft cushioning and also provides extra insulation while wading in cold water. Wallking and wading all day in the G4 Boat Boot is not a problem.

Field Test

The Eagle River is probably the toughest river to wade that Vail Valley Anglers guides on. It is slick, has fast current and the constantly uneven depths hide rocks that range from smooth rounded boulders to jagged obstacles. Winter is no doubt the hardest season to wade with slimy rocks made only more dangerous when they are coated in ice. The consequences for a wading misstep are much greater than in August when a short swim might be a welcome diversion. With this in mind, the G4 Boa Boot has done an outstanding job of keeping me on my feet while guiding on the Eagle this winter. This is a rubber sole that really does work (without cleats). It is the first time I’ve used a Boa lacing system and I like it a lot for the fit it provides. I don’t want to even think about my boots while I’m fly fishing. They should just work well while I forget about them and concentrate on catching fish and the G4 Boa Boot from Simms does just that.

For more information on wading boots stop by the Vail Valley Anglers full-service fly shop in Edwards, Colorado.

Brody Henderson, Guide and Content Writer