The weather outside may be chilly for sandals but Christmas gifts know no temperature.

A few months ago my ex rafting boss at Adventure Whitewater saw me eyeing his new Z2 Pro Chacos with diamond rubber soles while we were strapping kayaks on to his truck. “The rubber on these sandals will change your life,” he replied to my stares. Sounds like hyperbole to many folks, but anyone who has slipped their way through a boating season on slick-soled sandals knows that really grippy rubber is life changing. I figured I could use a little grip and some change in my life so I got a pair. Here’s how they stacked up.

I picked a boulder-strewn riverside takeout and conjured up as many sketchy portage scenarios as I could. I tested them in full gear with a playboat over my shoulder for realism. This threw off my balance and taxed the grip on the shoes with extra weight.

High step dry sandals: The high step has ripped trunks as well as slipped up many an unwitting boater. The slide-down from the high step usually conduces a face plant followed by a tumble back. In the test, the rubber gripped the rock like climbing shoes. I tested the purchase for a dry high step on steeply inclined rock as well and they stuck marvelously.

High step wet sandals: A true test of a sandal’s river worthiness is if its performance goes to shambles once it gets splashed. Their grippiness did not subside after total immersion when applied to dry rocks on a high step.

Wet sandals on mossy rocks: An inevitable portaging nightmare in the Northwest. Personally, I usually come across the moss when I’m on a steep incline perched over something really scary. There was some slippage in this category. The diamond rubber did not miraculously grip through the deep moss I was walking on. With that said, they did a great job of arresting the slip once they came in to contact with the moss-less part of the rock face.

Dry small landing jump: While the parkour guys make it look easy, landing on a small spot can be scary, dangerous, and basically impossible without proper foot grip. The first small landing was an oblong rock about 8 by 12 inches. I jumped about three feet to get to it. The Chacos gripped so well that my weight went over the rock and the awkwardness of my boat helped send me into the water. It was not slippage that caused the fall but rather surprise at how well they stuck. After many other attempts, I got the hang of it and stayed dry as well as impressed.

Conclusion: While these sandals and their spectacular grip have not helped me to self-actualize, I do know my self-confidence will improve as I tackle portages with less fear this spring. The diamond rubber lives up to its billing.