The KEEN H2 sandal has performed really well, it's got nice toe coverage, ventilation, and enough room for my wide feet.
I'm able to use it for my martial arts. I also used them in an obstacle course with my son last year, both of us actually wore them for the course.
We were in and out of the water, climbed over a little rock climbing wall, there was a rope swing, a big mud pit, and these stayed on my feet during the whole course.
They have a nice string drawstring to tighten up that grip on your foot.
Good ventilation, good grip on the bottom for going in and out of the water to sand or dry land, and are easy to slip on and off.
Overall, just a well put together sandal.
So well put together that we went and bought a pair for the entire family, for my wife, our little girl, and as you already saw, my son.
So if you're looking for hiking sandals, I highly recommend the KEEN H2.