At Kit Up! we recently had a reader asking about wrist worn GPS units, so here are a few of my thoughts on the subject, based on my previous experiences using the two models seen above during combat deployments to Iraq. I've used the Garmin Foretrex in New York City as well, and while it takes some time, it will eventually get reception despite the tall buildings interferring with the signal. Even out in the forest in NY, the Foretrex actually gets a stronger signal over in Iraq than it does when I go backpacking here in the United States.
On the right hand side is the Foretrex 101, the first generation Foretrex, which is probably six years old now. I ended up buying this one with my own money, but they were actually issuing these out in Ranger Battalion when they first hit the market. This was back in 2005 and I jumped all over the second generation model, the 201. This turned out to be a huge mistake. While the 101 runs on two AAA batteries, the 201 has a internal, non-removable, (supposedly) rechargeable battery. What happened when I got to Iraq? The recharger took a crap and I was left out there flapping. On my next deployment, I ended up going back a generation and picking up the 101 to take with me. Problem solved.
In terms of features, they are both essentially the same. While they don't store maps, they do show your breadcrumbs, waypoints, give you a date-time-group, a grid to your current location, measure how far you walked (or ran), and how fast you were moving, among other data. The breadcrumbs feature is the most helpful for finding your way, especially when negotiating the labyrinth like back streets in cities like Mosul.
Those breadcrumbs would also be helpful if you were running the fire breaks out in the woods at Ft. Bragg and got lost, turning your five mile run into something like a ten miler. Don't ask me how I know that.
Searching the web, I noticed that Garmin now has a 301 and 401 model out. Anybody out there have experience with these two GPS units that they can share with us?